Compiled by 2nd year student, 4 faculties,

1 group

Sokolov Maxim

Moscow 2003

1. Tasks, types

and organization of biochemical control.

2. Objects of research.

3. Basic biochemical indicators of blood and urine composition, their changes during muscle activity.

4. Biochemical control of the development of energy supply systems for the body during muscle activity.

5. Biochemical control over the level of training, fatigue and recovery of the athlete’s body.

6. Control over the use of doping in sports.

BiochemicalcontrolVsports

When the body adapts to physical activity, overtraining, as well as in pathological conditions, the body's metabolism changes, which leads to the appearance in various tissues and biological fluids of individual metabolites (metabolic products), which reflect functional changes and can serve as biochemical tests or indicators of them characteristics. Therefore, in sports, along with medical, pedagogical, psychological and physiological control, biochemical control over the functional state of the athlete is used.

In the practice of elite sports, complex scientific examinations of athletes are usually carried out, providing complete and objective information about the functional state of individual systems and the entire body, and its readiness to perform physical activity. Such control at the level of the national teams of the country is carried out by complex scientific groups (CSG), which include several specialists: a biochemist, a physiologist, a psychologist, a doctor, and a coach.

1. Tasks, kinds

Andorganizationbiochemicalcontrol

Determination of biochemical indicators of metabolism allows solving the following tasks of a comprehensive examination: monitoring the functional state of the athlete’s body, which reflects the effectiveness and rationality of the individual training program being performed, monitoring adaptive changes in the main energy systems and functional restructuring of the body during training, diagnosing pre-pathological and pathological changes in metabolism athletes. Biochemical control also makes it possible to solve such particular problems as identifying the body’s response to physical activity, assessing the level of fitness, the adequacy of the use of pharmacological and other restorative agents, the role of energy metabolic systems in muscle activity, the impact of climatic factors, etc. In this regard, in the practice of sports biochemical control is used at various stages of athletes' training.

In the annual training cycle of qualified athletes, different types of biochemical control are distinguished:

Routine examinations (TO) carried out on a daily basis in accordance with the training plan;

Staged comprehensive examinations (IVF), carried out 3-4 times
in year;

In-depth comprehensive examinations (ICS), carried out 2 times
in year;

Competitive Activity Survey (CAS).

Based on current examinations, the athlete’s functional state is determined - one of the main indicators of fitness, the level of immediate and delayed training effect of physical activity is assessed, and physical activity is corrected during training.

In the process of staged and in-depth comprehensive examinations of athletes, the cumulative training effect can be assessed using biochemical indicators, and biochemical control provides the coach, teacher or doctor with quick and fairly objective information about the growth of fitness and functional systems of the body, as well as other adaptive changes.

When organizing and conducting a biochemical examination, special attention is paid to the selection of testing biochemical indicators: they must be reliable or reproducible, repeatable during multiple control examinations, informative, reflecting the essence of the process being studied, as well as valid or interrelated with sports results.

In each specific case, different testing biochemical indicators of metabolism are determined, since in the process of muscle activity individual links of metabolism change differently. The indicators of those metabolic components that are fundamental in ensuring athletic performance in a given sport acquire paramount importance.

Of no small importance in a biochemical examination are the methods used to determine metabolic parameters, their accuracy and reliability. Currently, in sports practice, laboratory express methods for determining many (about 60) different biochemical parameters in blood plasma using a portable 1P-400 device from the Swiss company “Doctor Lange” or other companies are widely used. Express methods for determining the functional state of athletes also include those proposed by academician V.G. Shakhbazov has a new method for determining the energy state of a person, which is based on changes in the bioelectric properties of the nuclei of epithelial cells depending on the physiological state of the body. The

The method allows us to identify disturbances in the body’s homeostasis, a state of fatigue and other changes in muscle activity.

Monitoring the functional state of the body in the conditions of a training camp can be carried out using special diagnostic express kits for biochemical analysis of urine and blood. They are based on the ability of a certain substance (glucose, protein, vitamin C, ketone bodies, urea, hemoglobin, nitrates, etc.) to react with reagents applied to the indicator strip and change color. Usually, a drop of the test urine is applied to the indicator strip of “Glucotest”, “Pentafan”, “Medi-test” or other diagnostic tests and after 1 minute its color is compared with the indicator scale attached to the kit.

The same biochemical methods and indicators can be used to solve various problems. For example, determination of lactate content in the blood is used to assess the level of training, focus and effectiveness of the exercise used, as well as when selecting individuals for individual sports.

Depending on the tasks being solved, the conditions for conducting biochemical research change. Since many biochemical indicators in a trained and untrained body in a state of relative rest do not differ significantly, to identify their characteristics, an examination is carried out at rest in the morning on an empty stomach (physiological norm), during the dynamics of physical activity or immediately after it, as well as during different periods of recovery.

When examining athletes, various types of testing physical activity are used, which can be standard and maximum (limit).

Standard physical loads - These are loads under which the amount and power of work performed are limited, which is ensured with the help of special devices - ergometers. The most commonly used are stepergometry (climbing at a different pace on a step or ladder of different heights, for example, the Harvard step test), bicycle ergometry (fixed work on a bicycle ergometer), and loads on a treadmill - a belt moving at a fixed speed. Currently, there are diagnostic complexes that allow you to perform special dosed physical activity: swimming treadmill, rowing ergometers, inertial bicycle ergometers, etc. Standard physical activity helps identify individual metabolic differences and is used to characterize the level of fitness of the body.

Maximum physical loads are used to identify the level of special training of an athlete at different stages of training. In this case, the loads most typical for this sport are used. They are performed with the highest possible intensity for this exercise.

When choosing test loads, it should be taken into account that the human body’s response to physical load may depend on factors not directly related to the level of training, in particular on the type of exercise being tested, the athlete’s specialization, as well as on the environment, ambient temperature, time of day, etc. By doing the usual work, an athlete can carry out a large volume of work and achieve significant metabolic changes in the body. This is especially clearly manifested when testing anaerobic capabilities, which are very specific and manifest themselves to the greatest extent only during work to which the athlete is adapted. Consequently, bicycle ergometer tests are most suitable for cyclists, treadmill tests for runners, etc. However, this does not mean that bicycle ergometer tests cannot be used for track and field athletes or athletes of other sports, which allow the most accurate calculation of the amount of work performed. However, cyclists will have an advantage in bicycle ergometer testing compared to representatives of other sports of the same qualifications and specializing in exercises related to the same power zone.

The test loads used, specific in power and duration, must correspond to the loads used by the athlete during training. Thus, for track and field runners specializing in short and ultra-long distances, testing loads should be different, facilitating the manifestation of their main motor qualities - speed or endurance. An important condition for the use of tested physical activity is the precise determination of its power or intensity and duration.

The results of the study are also affected by ambient temperature, testing time and health status. Lower performance is observed at elevated ambient temperatures, as well as in the morning and evening. Only completely healthy athletes should be allowed to test, as well as to engage in sports, especially with maximum loads, therefore a medical examination should precede other types of control. Control biochemical testing is carried out in the morning on an empty stomach after relative rest for 24 hours. In this case, approximately the same environmental conditions must be observed, which affect the test results.

Changes in biochemical parameters under the influence of physical activity depend on the degree of training, the volume of exercise performed, their intensity and anaerobic or aerobic orientation, as well as on the gender and age of the subjects. After standard physical activity, significant biochemical changes are found in less trained people, and after maximum physical activity, in highly trained people. Moreover, after performing loads specific to athletes under competition conditions or in the form of estimates, significant biochemical changes are possible in a trained body that are not typical for untrained people.

2. Objects of research

and basic biochemical parameters

The objects of biochemical research are exhaled air and biological fluids - blood, urine, saliva, sweat, as well as muscle tissue.

Exhaled air - one of the main objects of study of energy metabolism processes in the body, the use of individual energy sources in the energy supply of muscle activity. It determines the amount of oxygen consumed and carbon dioxide exhaled. The ratio of these indicators to a certain extent reflects the intensity of energy exchange processes, the share of anaerobic and aerobic mechanisms of ATP resynthesis in them.

Blood is used as one of the most important objects of biochemical research, since it reflects all metabolic changes in tissue fluids and lymph of the body. By changes in the composition of blood or its liquid part - plasma, one can judge the homeostatic state of the internal environment of the body or its change during sports activity (Table 1).

Many studies require a small amount of blood (0.01-0.05 ml), so it is taken from the ring finger of the hand or from the rib of the earlobe. After performing physical work, blood sampling

TABLE 1. BasicchemicalComponentswholebloodAndplasmagreatwowadultperson

During physical activity and exposure to other environmental factors, as well as during pathological changes in metabolism or after the use of pharmacological agents, the content of individual blood components changes significantly. Consequently, based on the results of a blood test, it is possible to characterize a person’s health status, level of fitness, the course of adaptation processes, etc. In recent years, due to the threat of AIDS infection, blood tests must be carried out in compliance with all prescribed protective measures.

Urine to a certain extent reflects the work of the kidneys - the main excretory organ of the body, as well as the dynamics of metabolic processes in various organs and tissues. Therefore, by changes in its quantitative and qualitative composition, one can judge the state of individual parts of metabolism, their excess intake, and disruption of homeostatic reactions in the body, including those associated with muscle activity. Excess water, many electrolytes, intermediate and final metabolic products, hormones, vitamins, and foreign substances are removed from the body with urine (Table 2). The daily amount of urine (diuresis) normally averages 1.5 liters. Urine is collected throughout the day, which introduces certain difficulties in conducting research. Sometimes urine is taken in fractional portions (for example, after 2 hours), and the portions obtained before and after physical work are recorded. Urine cannot be a reliable object of study after short-term training loads, since immediately after this it is very difficult to collect the amount necessary for its analysis.

In various functional states of the body, chemical substances that are not typical for the norm may appear in the urine: glucose, protein, ketone bodies, bile pigments, blood cells, etc. The determination of these substances in the urine can be used in the biochemical diagnosis of certain diseases, as well as in practice sports to monitor the effectiveness of the training process and the athlete’s health status.

TABLE 2 Chemicalcompound

urinehealthy adultperson

Saliva usually used in parallel with

other biochemical objects. In saliva, electrolytes (N3 and K), enzyme activity (amylase), and pH are determined. There is an opinion that saliva, having a smaller buffer capacity than blood, better reflects changes in the acid-base balance of the human body. However, as an object of research, saliva is not widely used, since its composition depends not only on physical activity and associated changes in interstitial metabolism, but also on the state of satiety (“hungry” or “full” saliva).

Sweat V in some cases it is of interest as an object of study. The amount of sweat required for analysis is collected using cotton linen or a towel, which is soaked in distilled water to extract the various components of sweat. The extract is evaporated in vacuum and analyzed.

Muscular textile is a very indicative object for biochemical control of muscle activity, but is rarely used, since a sample of muscle tissue must be taken methodneedle-shapedbiopsy. To do this, a small skin incision is made over the muscle being examined and a piece (sample) of muscle tissue (2-3 mg) is taken using a special needle, which is immediately frozen in liquid nitrogen and subsequently subjected to structural and biochemical analysis. The samples determine the amount of contractile proteins (actin and myosin), ATPase activity of myosin, energy potential indicators (ATP, glycogen, creatine phosphate content), energy metabolism products, electrolytes and other substances. Their content is used to judge the composition and functional activity of muscles, its energy potential, as well as changes that occur under the influence of a single physical activity or long-term training.

During biochemical examination in sports practice, the following biochemical indicators are used:

Energy substrates (ATP, CrP, glucose, free fatty acids);

Enzymes of energy metabolism (ATPase, CrP kinase, cytochrome oxidase, lactate dehydrogenase, etc.);

Intermediate and final products of metabolism of carbohydrates, lipids and proteins (lactic and pyruvic acids, ketone bodies, urea, creatinine, creatine, uric acid, carbon dioxide, etc.); indicators of the acid-base state of the blood (blood pH, partial pressure of CO2, reserve alkalinity or excess buffer bases, etc.);

Metabolic regulators (enzymes, hormones, vitamins, activators, inhibitors);

Minerals in biochemical fluids (for example, bicarbonates and phosphoric acid salts are determined to characterize the buffering capacity of the blood);

Anabolic steroids and other prohibited substances in sports practice (doping), the identification of which is the task of doping control.

3. BasicbiochemicalindicatorscompositionbloodAndurine,theirchangeatmuscularactivities

Indicators carbohydrate metabolism

Glucose. The glucose content in the blood is maintained at a relatively constant level by special regulatory mechanisms within the range of 3.3-5.5 mmol l "1 (80-120 mg%). The change in its content in the blood during muscle activity is individual and depends on the level of fitness of the body, power and duration of exercise. Short-term exercise of submaximal intensity can cause an increase in blood glucose due to increased mobilization of liver glycogen. Long-term exercise leads to a decrease in blood glucose. In untrained individuals, this decrease is more pronounced than in trained individuals. Increased glucose levels in the blood indicates intensive breakdown of liver glycogen or relatively low use of glucose by tissues, and its reduced content indicates depletion of liver glycogen reserves or intensive use of glucose by body tissues.

The change in glucose content in the blood is used to judge the rate of its aerobic oxidation in body tissues during muscle activity and the intensity of mobilization of liver glycogen. This indicator of carbohydrate metabolism is rarely used independently in sports diagnostics, since the level of glucose in the blood depends not only on the effect of physical activity on the body, but also on the emotional state of a person, humoral regulatory mechanisms, nutrition and other factors.

In a healthy person, there is no glucose in the urine, but it can appear during intense muscle activity, emotional arousal before the start and with an excess intake of carbohydrates from food (nutritional glucosuria)V as a result of an increase in its level in the blood (condition hyperglycemia). The appearance of glucose in the urine during exercise indicates intensive mobilization of liver glycogen. The constant presence of glucose in the urine is a diagnostic test for diabetes mellitus.

Dairy acid. The glycolytic mechanism of ATP resynthesis in skeletal muscles ends with the formation of lactic acid, which then enters the blood. Its release into the blood after stopping work occurs gradually, reaching a maximum at 3-7 minutes after the end of work. Milk content

acid in the blood normally in a state of relative rest is 1-1.5 mmol l "1 (15-30 mg%) and increases significantly when performing intense physical work. Moreover, its accumulation in the blood coincides with increased formation in the muscles, which is significantly increases after intense short-term exercise and can reach about 30 mmol kg1 of mass during exhaustion. The amount of lactic acid is greater in venous blood than in arterial blood. With increasing load power, its content in the blood can increase in an untrained person to 5-6 mmol l "1, in a trained person - up to 20 mmol l~1 and higher. In the aerobic zone of physical activity, lactate is 2-4 mmol l~1, in the mixed zone - 4-10 mmol l~1, in anaerobic zone - more than 10 mmol l~1. The conventional limit of anaerobic metabolism corresponds to 4 mmol of lactate in 1 liter of blood and is designated as the threshold of anaerobic metabolism (TANT), or lactate threshold (LT). A decrease in lactate content in the same athlete when performing standard work at different stages of the training process indicates an improvement in fitness, and an increase indicates a deterioration. Significant concentrations of lactic acid in the blood after performing maximum work indicate a higher level of training with good athletic results or a greater metabolic capacity of glycolysis, greater resistance of its enzymes to a pH shift to the acidic side. Thus, the change in the concentration of lactic acid in the blood after performing a certain physical activity is associated with the athlete’s state of fitness. By changing its content in the blood, the anaerobic glycolytic capabilities of the body are determined, which is important when selecting athletes, developing their motor qualities, monitoring training loads and the progress of the body’s recovery processes.

Indicators lipid exchange

Available fatty acids . Being structural components of lipids, the level of free fatty acids in the blood reflects the rate of lipolysis of triglycerides in the liver and fat depots. Normally, their content in the blood is 0.1-0.4 mmol l"1 and increases with prolonged physical activity.

By changing the content of FFAs in the blood, the degree of connection of lipids to the processes of energy supply to muscle activity is monitored, as well as the efficiency of energy systems or the degree of coupling between lipid and carbohydrate metabolism. A high degree of coupling of these energy supply mechanisms when performing aerobic exercise is an indicator of a high level of functional training of an athlete.

Ketones body . They are formed in the liver from acetyl-CoA with increased oxidation of fatty acids in the tissues of the body. Ketone bodies from the liver enter the blood and are delivered to tissues, in which most are used as an energy substrate, and a smaller part is excreted from the body. The level of ketone bodies in the blood to a certain extent reflects the rate of fat oxidation. The normal content of ketone bodies in the blood is relatively low - 8 mmol l~1. With accumulation in the blood up to 20 mmol l~1 (ketonemia) they may appear in the urine, whereas normally ketone bodies are not detected in urine. Their appearance in urine (ketonuria) in healthy people it is observed during fasting, excluding carbohydrates from the diet, as well as when performing physical activity of high power or duration. This indicator also has diagnostic value in identifying diabetes mellitus and thyrotoxicosis.

An increase in the content of ketone bodies in the blood and their appearance in the urine determines the transition of energy production from carbohydrate sources to lipid sources during muscle activity. An earlier connection of lipid sources indicates the efficiency of aerobic mechanisms for energy supply to muscle activity, which is interconnected with an increase in the body's fitness.

Cholesterol . This is a representative of steroid lipids that is not involved in the processes of energy formation in the body. The cholesterol content in blood plasma is normally 3.9-6.5 mmol l"1 and depends on gender (higher in men), age (lower in children), diet (lower in vegetarians), physical activity. Constant increase in cholesterol levels and its individual lipoprotein complexes in the blood plasma serves as a diagnostic test for the development of a serious disease - atherosclerosis, accompanied by damage to blood vessels. The dependence of coronary disorders on the concentration of cholesterol in the blood has been established. When the vessels of the heart are damaged, myocardial ischemia or infarction is observed, and the vessels of the brain - strokes, and the vessels of the legs - atrophy of the limbs. Recent studies have shown that dietary fiber (fiber) contained in vegetables, fruits, brown bread and other products, as well as lecithin and systematic exercise, help remove cholesterol from the human body.

Products peroxide oxidation lipids ( FLOOR ). During physical activity, lipid peroxidation processes intensify and the products of these processes accumulate, which is one of the factors limiting physical performance. Therefore, when biochemically monitoring the body’s response to physical activity, assessing the special preparedness of an athlete, identifying the depth of biodestructive processes during the development of stress syndrome, the content of peroxidation products in the blood is analyzed: malondialdehyde, diene conjugates, as well as the activity of the enzymes glutathione peroxidase, glutathione reductase and catalase.

Phospholipids . The normal content of phospholipids in the blood is 1.52-3.62 g l~1. An increase in their level in the blood is observed with diabetes, kidney disease, hypofunction of the thyroid gland and other metabolic disorders, and a decrease is observed with fatty liver degeneration, i.e. when the liver structures in which they are synthesized are affected. To stimulate the synthesis of phospholipids and reduce the content of triglycerides in the blood, it is necessary to increase the dietary intake of lipotropic substances. Since long-term physical activity is accompanied by fatty degeneration of the liver, in sports practice they sometimes use control of the content of triglycerides and phospholipids in the blood.

Indicators protein exchange

Hemoglobin . The main protein of red blood cells is hemoglobin, which performs an oxygen transport function. It contains iron, which binds oxygen in the air. The concentration of hemoglobin in the blood depends on gender and averages 7.5-8.0 mmol l~1 (120-140 g l~1) in women and 8.0-10.0 mmol l~1 (140-160 g l~1) - in men, as well as on the degree of training. During muscular activity, the body's need for oxygen sharply increases, which is satisfied by more complete extraction of it from the blood, an increase in the speed of blood flow, as well as a gradual increase in the amount of hemoglobin in the blood due to changes in the total mass of blood. With an increase in the level of training of athletes in endurance sports, the concentration of hemoglobin in the blood in women increases on average to 130-150 g l"1, in men - to 160-180 g l~1. The increase in hemoglobin content in the blood to a certain extent reflects adaptation body to physical activity under hypoxic conditions.

With intense training, especially in women involved in cyclic sports, as well as poor nutrition, destruction of red blood cells occurs and the hemoglobin concentration decreases to 90 g l "1 and below, which is considered as iron deficiency "sports anemia". In this case, the program should be changed training, and increase the content of protein foods, iron and B vitamins in the diet.

Myoglobin . In the sarcoplasm of skeletal and cardiac muscles there is a highly specialized protein that performs the function of transporting oxygen like hemoglobin. The content of myoglobin in the blood is normally insignificant (10-70 ng l~1). Under the influence of physical activity, in pathological conditions of the body, it can leave the muscles into the blood, which leads to an increase in its content in the blood and appears in the urine (myoglobinuria). The amount of myoglobin in the blood depends on the amount of physical activity performed, as well as on the degree of training of the athlete. Therefore, this indicator can be used to diagnose the functional state of working skeletal muscles.

Actin . The content of actin in skeletal muscles as a structural and contractile protein increases significantly during training. Based on its content in the muscles, it would be possible to monitor the development of the speed-strength qualities of an athlete during training, but determining its content in the muscles is associated with great methodological difficulties. However, after physical exercise, actin appears in the blood, which indicates the destruction or renewal of the myofibrillar structures of skeletal muscles. The actin content in the blood is determined using the radioimmunological method and its changes are used to judge the tolerance of physical activity and the intensity of myofibril recovery after muscular work.

Albumin And globulins . These are low molecular weight basic proteins of blood plasma. Albumins make up 50-60% of all blood serum proteins, globulins - 35-40%. They perform various functions in the body: they are part of the immune system, especially globulins, and protect the body from infections, participate in maintaining blood pH, transport various organic and inorganic substances, and are used to build other substances. Their quantitative ratio in blood serum is normally relatively constant and reflects the state of human health. The ratio of these proteins changes during fatigue and many diseases and can be used in sports medicine as a diagnostic indicator of health status.

Urea . With increased breakdown of tissue proteins and excess intake of amino acids into the body, a non-toxic nitrogen-containing substance - urea - is synthesized in the liver in the process of binding ammonia (MH3), which is toxic to the human body. From the liver, urea enters the blood and is excreted in the urine.

The normal concentration of urea in the blood of each adult is individual - within the range of 3.5-6.5 mmol l~1. It can increase to 7-8 mmol l~1 with a significant intake of proteins from food, up to 16-20 mmol l~1 - if the excretory function of the kidneys is impaired, as well as after prolonged physical work due to increased protein catabolism up to 9 mmol l" 1 or more.

In sports practice, this indicator is widely used to assess an athlete’s tolerance to training and competitive physical activity, the progress of training sessions and the body’s recovery processes. To obtain objective information, urea concentration is determined the next day after training in the morning on an empty stomach. If the physical activity performed is adequate to the functional capabilities of the body and a relatively rapid restoration of metabolism has occurred, then the urea content in the blood in the morning on an empty stomach returns to normal (Fig. 1). This is due to balancing the rate of synthesis and breakdown of proteins in the tissues of the body, which indicates its restoration. If the urea content remains above normal the next morning, this indicates a lack of recovery of the body or the development of fatigue.

Detection squirrel V urine . A healthy person does not have protein in their urine. His appearance (proteinuria) It is observed with kidney disease (nephrosis), damage to the urinary tract, as well as with excessive intake of proteins from food or after anaerobic muscular activity. This is due to a violation of the permeability of the cell membranes of the kidneys due to acidification of the body’s environment and the release of plasma proteins into the urine.

By the presence of a certain concentration of protein in the urine after performing physical work, its power is judged. So, when working in a high power zone it is 0.5%, when working in a submaximal power zone it can reach 1.5%.

Rice . 1

urea in the blood

rowers during

rest (1.5 hours, 5 hours and

morning after

training day):

1 - complete

recovery;

2, 3 - different

under-recovery

Original

urea

next day

Creatinine . This substance is formed in muscles during the breakdown of creatine phosphate. Its daily excretion in urine is relatively constant for a given person and depends on the muscle mass of the body. In men it is 18-32 mg kg"1 body weight per day, in women - 10-25 mg kg"1. The creatinine content in urine can indirectly estimate the rate of the creatine phosphokinase reaction, as well as the content of lean body mass. Based on the amount of creatinine excreted in the urine, the content of lean muscle mass of the body is determined according to the following formula:

lean body mass = 0.0291 x urine creatinine (mg day~1) + 7.38.

A change in the amount of lean body mass indicates a decrease or increase in the athlete’s body weight due to proteins. These data are important in athletic gymnastics and strength sports.

Creatine . Normally, there is no creatine in the urine of adults. It is detected during overtraining and pathological changes in muscles, so the presence of creatine in the urine can be used as a test to determine the body's response to physical activity.

Creatine is constantly present in the urine of young children, which is associated with the predominance of its synthesis over its use in skeletal muscles.

Indicators acidic main states ( CBS) body

During intense muscular activity, large amounts of lactic and pyruvic acids are formed in the muscles, which diffuse into the blood and can cause metabolic acidosis of the body, which leads to muscle fatigue and is accompanied by muscle pain, dizziness, and nausea. Such metabolic changes are associated with the depletion of the body's buffer reserves. Since the state of the body's buffer systems is important in the manifestation of high physical performance, CBS indicators are used in sports diagnostics. The CBS indicators, which are normally relatively constant, include:

Blood pH (7.35-7.45);

PCO2 - partial pressure of carbon dioxide (H2CO3 + CO2) in the blood (35-45 mm Hg);

5B - standard blood plasma bicarbonate HSOd, which, when the blood is completely saturated with oxygen, is 22-26 meq l"1;

BB - buffer bases of whole blood or plasma (43-53 meq -l"1) - an indicator of the capacity of the entire buffer system of blood or plasma;

L/86 - normal buffer bases of whole blood at physiological values ​​of pH and CO2 of alveolar air;

BE - excess bases, or alkaline reserve (from -2.4 to +2.3 meq -l "1) - an indicator of excess or lack of buffer capacity (BB - YVV = BE).

CBS indicators reflect not only changes in the blood buffer systems, but also the state of the respiratory and excretory systems of the body. The state of acid-base balance (ABC) in the body is characterized by a constant blood pH (7.34-7.36). Reverse core installed

TABLE 3

Change

acidic- main

state

body

Note. The direction of the arrow indicates an increase or decrease in indicators

relational relationship between the dynamics of lactate content in the blood and changes in blood pH. By changing the ABS indicators during muscle activity, it is possible to monitor the body’s response to physical activity and the growth of the athlete’s fitness, since with the biochemical control of the ABS, one of these indicators can be determined.

The most informative indicator of CBS is the value BE - alkaline reserve, which

increases with the improvement of the qualifications of athletes, especially those specializing in speed-strength sports. Large buffer reserves of the body are a serious prerequisite for improving athletic performance in these sports.

Active reaction urine ( pH ) is directly dependent on the acid-base state of the body. With metabolic acidosis, urine acidity increases to pH 5, and with metabolic alkalosis it decreases to pH 7. Table. Figure 3 shows the direction of changes in urine pH values ​​in relation to indicators of the acid-base state of plasma (according to T.T. Berezov and B.F. Korovkin, 1998).

Biologically active substances - regulators exchange substances

Enzymes . Of particular interest in sports diagnostics are tissue enzymes, which, under various functional states of the body, enter the blood from skeletal muscles and other tissues. Such enzymes are called cellular, or indicator. These include aldolase, catalase, lactate dehydrogenase, creatine kinase, etc. Individual cellular enzymes, for example skeletal muscle lactate dehydrogenase, are characterized by the presence of several forms (isoenzymes). The appearance of indicator enzymes or their individual isoforms in the blood, which is associated with impaired permeability of cell membranes of tissues, can be used in biochemical monitoring of the functional state of an athlete.

In sports practice, the presence in the blood of such tissue enzymes of the processes of biological oxidation of substances is often determined, such as aldolase - an enzyme of glycolysis and catalase - an enzyme that reduces hydrogen peroxides. Their appearance in the blood after physical activity is an indicator of inadequacy of physical activity and the development of fatigue, and the speed of their disappearance indicates the speed of recovery of the body.

After physical exercise, individual isoforms of enzymes may appear in the blood - creatine kinase, lactate dehydrogenase, characteristic of a particular tissue. Thus, after prolonged physical exercise, an isoform of creatine phosphokinase, characteristic of skeletal muscles, appears in the blood of athletes; During acute myocardial infarction, an isoform of creatine kinase, characteristic of the heart muscle, appears in the blood. If physical activity causes a significant release of enzymes into the blood from the tissues and they remain in it for a long time during the rest period, then this indicates a low level of training of the athlete, and, possibly, a pre-pathological state of the body.

Hormones , When biochemically diagnosing the functional state of an athlete, the level of hormones in the blood is an informative indicator. More than 20 different hormones that regulate different parts of metabolism can be determined. The concentration of hormones in the blood is quite low and usually varies from 10~8 to 10~11 mol l~1, which makes it difficult to widely use these indicators in sports diagnostics. The main hormones that are used to assess the functional state of an athlete, as well as their normal concentration in the blood and the direction of change during standard physical activity are presented in Table. 4.

The magnitude of the change in the content of hormones in the blood depends on the power and duration of the loads performed, as well as on the degree of training of the athlete. When working at the same power, more trained athletes experience less significant changes in these indicators in the blood. In addition, by changes in the content of hormones in the blood, one can judge the body’s adaptation to physical activity, the intensity of metabolic processes regulated by them, the development of fatigue processes, the use of anabolic steroids and other hormones.

Vitamins . Detection of vitamins in urine is included in the diagnostic complex of characterizing the health status of athletes and their physical performance. In the practice of sports, the body's supply of water-soluble vitamins, especially vitamin C, is most often revealed. Vitamins appear in the urine when the body is sufficiently supplied with them. Data from numerous studies indicate that many athletes are insufficiently supplied with vitamins, so monitoring their content in the body will make it possible to timely adjust the diet or prescribe additional vitamin supplementation by taking special multivitamin complexes.

Mineral substances In the muscles, inorganic phosphate is formed in the form of phosphoric acid (H3P04) during transphosphorylation reactions in the creatine phosphokinase mechanism of ATP synthesis and other processes. By changing its concentration in the blood, one can judge the power of the creatine phosphokinase energy supply mechanism in athletes, as well as the level of training, since the increase in inorganic phosphate in the blood of highly qualified athletes when performing anaerobic physical work is greater than in the blood of less qualified athletes.

Table 4 . The direction of changes in the concentration of hormones in the blood during physical exercise.

4. Biochemicalcontroldevelopmentsystemsenergy supplyvaluesbodyatmuscularactivities

Sports performance is to a certain extent limited by the level of development of the body's energy supply mechanisms. Therefore, in the practice of sports, the power, capacity and efficiency of anaerobic and aerobic mechanisms of energy generation during training are monitored, which can also be done using biochemical indicators.

To assess the power and capacity of the creatine phosphokinase mechanism of energy production, indicators of total alactic oxygen debt, the amount of creatine phosphate and the activity of creatine phosphokinase in muscles are used. In a trained body, these indicators are significantly higher, which indicates an increase in the capabilities of the creatine phosphokinase (alactate) mechanism of energy production.

The degree of activation of the creatine phosphokinase mechanism during physical activity can also be assessed by an increase in the blood content of CrP metabolic products in the muscles (creatine, creatinine and inorganic phosphate) or a change in their content in the urine.

To characterize the glycolytic mechanism of energy production, the value of the maximum accumulation of lactate in arterial blood during maximum physical exertion is often used, as well as the value of total and lactate oxygen debt, blood pH and CBS indicators, blood glucose and glycogen levels in muscles, activity of the enzymes lactate dehydrogenase, phosphorylase and etc.

An increase in the potential for glycolytic (lactate) energy production in athletes is evidenced by a later achievement of the maximum amount of lactam in the blood during extreme physical exertion, as well as its higher level. In highly qualified athletes specializing in high-speed sports, the amount of lactate in the blood during intense physical activity can increase to 26 mmol l"1 or more, while in untrained people the maximum tolerated amount of lactate is 5-6 mmol l"1, and 10 mmol l~1 can be fatal at a functional norm of 1-1.5 mmol-l"1. An increase in the capacity of glycolysis is accompanied by an increase in glycogen reserves in skeletal muscles, especially in fast fibers, as well as an increase in the activity of glycolytic enzymes.

To assess the power of the aerobic mechanism of energy production, the level of maximum oxygen consumption (MIC or IE2max), the time of onset of PANO, as well as an indicator of the oxygen transport system of the blood - hemoglobin concentration are most often used. An increase in the level of 1/O2max indicates an increase in the power of the aerobic energy generation mechanism. The maximum oxygen consumption in adults who do not engage in sports is 3.5 l min"1 for men, 2.0 l min"1 for women and depends on body weight. In highly qualified athletes, the absolute value of 1/O2max in men can reach 6-7 l min"1, in women - 4-5 l min"1.

Based on the duration of operation at the ANSP level, an increase in the capacity of the energy generation mechanism is judged. Untrained people cannot perform physical work at the ANSP level for more than 5-6 minutes. For athletes specializing in endurance, the duration of work at the PANO level can reach 1-2 hours.

The efficiency of the aerobic mechanism of energy production depends on the rate of oxygen utilization by mitochondria, which is associated primarily with the activity and quantity of oxidative phosphorylation enzymes, the number of mitochondria, as well as the proportion of fats during energy formation. Under the influence of intense aerobic training, the efficiency of the aerobic mechanism increases due to an increase in the rate of fat oxidation and an increase in their role in the energy supply of work.

5. Biochemicalcontrolbehindlevelfitness level, fatigueAndrecoverybodyathlete

Level fitness level in the practice of biochemical monitoring of the functional state of an athlete, it is assessed by changes in the concentration of lactate in the blood when performing standard or maximum physical activity for a given contingent of athletes. A higher level of training is evidenced by lower accumulation of lactate (compared to untrained people) when performing a standard load, which is associated with an increase in the share of aerobic mechanisms in the energy supply of this work;

Greater accumulation of lactic acid when performing extreme work, which is associated with an increase in the capacity of the glycolytic energy supply mechanism;

An increase in PANO (the power of work at which the level of lactate in the blood sharply increases) in trained individuals compared to untrained individuals;

Longer work at the ANSP level;

Smaller increase in blood lactate with increasing
operating power, which is explained by the improvement of anaerobic processes and efficiency

energy expenditure of the body;

Increasing the rate of lactate utilization during the recovery period after exercise.

With an increase in the level of training of athletes in endurance sports, the total blood mass increases: in men - from 5-6 to 7-8 l, in women - from 4-4.5 to 5.5-6 l, which leads to an increase in concentration hemoglobin up to 160-180 g l"1 - in men and up to 130-150 g l"1 - in women.

Monitoring the processes of fatigue and recovery, which are integral components of sports activity, is necessary to assess exercise tolerance and identify overtraining, sufficient rest time after physical activity, the effectiveness of means of increasing performance, as well as to solve other problems.

Fatigue , caused by physical activity of maximum and submaximal power, is associated with the depletion of energy substrates (ATP, CrP, glycogen) in the tissues that provide this type of work, and the accumulation of their metabolic products in the blood (lactic acid, creatine, inorganic phosphates), and therefore is controlled by these indicators. When performing prolonged hard work, the development of fatigue can be detected by a prolonged increase in the level of urea in the blood after work, by changes in the components of the immune system of the blood, as well as by a decrease in the content of hormones in the blood and urine.

In sports diagnostics, to identify fatigue, the content of hormones of the sympatho-adrenal system (adrenaline and its metabolic products) in the blood and urine is usually determined. These hormones are responsible for the degree of tension of adaptive changes in the body. When physical activity is inadequate to the functional state of the body, there is a decrease in the level of not only hormones, but also the precursors of their synthesis in the urine, which is associated with the depletion of the biosynthetic reserves of the endocrine glands and indicates an overstrain of the body’s regulatory functions that control adaptation processes.

For early diagnosis of overtraining, the latent phase of fatigue, monitoring of the functional activity of the immune system is used. To do this, determine the number and functional activity of T- and B-lymphocyte cells: T-lymphocytes provide the processes of cellular immunity and regulate the function of B-lymphocytes; B lymphocytes are responsible for the processes of humoral immunity; their functional activity is determined by the amount of immunoglobulins in the blood serum.

Determining the components of the immune system requires special conditions and equipment. When connecting immunological monitoring of the functional state of an athlete, it is necessary to know his initial immunological status with subsequent monitoring at various periods of the training cycle. Such control will prevent the breakdown of adaptation mechanisms, exhaustion of the immune system and the development of infectious diseases of highly qualified athletes during periods of training and preparation for important competitions (especially during sudden changes in climatic zones).

Recovery the body is associated with the renewal of the amount of energy substrates and other substances consumed during work. Their restoration, as well as the rate of metabolic processes, do not occur simultaneously (see Chapter 18). Knowing the recovery time of various energy substrates in the body plays a big role in the correct construction of the training process. The recovery of the body is assessed by changes in the amount of those metabolites of carbohydrate, lipid and protein metabolism in the blood or urine that change significantly under the influence of training loads. Of all the indicators of carbohydrate metabolism, the rate of utilization of lactic acid during rest is most often studied, as well as lipid metabolism - the increase in the content of fatty acids and ketone bodies in the blood, which during the rest period are the main substrate of aerobic oxidation, as evidenced by a decrease in the respiratory coefficient. However, the most informative indicator of the body’s recovery after muscular work is the product of protein metabolism - urea. During muscle activity, the catabolism of tissue proteins increases, which contributes to an increase in the level of urea in the blood, therefore the normalization of its content in the blood indicates the restoration of protein synthesis in the muscles, and, consequently, the restoration of the body.

6. ControlbehindapplicationdopingVsports

At the beginning of the XX century. in sports, to increase physical performance, accelerate recovery processes, and improve athletic performance, various stimulant drugs, including hormonal, pharmacological and physiological, the so-called doping, began to be widely used. Their use not only creates unequal conditions in wrestling, but also causes harm to the athlete’s health as a result of side effects, and sometimes causes death. Regular use of doping agents, especially hormonal drugs, causes disruption of the functions of many physiological systems:

Cardiovascular;

Endocrine, especially the gonads (atrophy) and pituitary gland, which leads to impaired reproductive function, the appearance of male secondary signs in women (virilization) and enlargement of the mammary glands in men (gynecomastia);

Liver, causing jaundice, edema, cirrhosis;

Immune, which leads to frequent colds and viral diseases;

Nervous, manifested in the form of mental disorders (aggression, depression, insomnia);

Stopping the growth of tubular bones, which is especially dangerous for a growing organism, etc.

Many disorders do not appear immediately after the use of doping agents, but after 10-20 years or in the offspring. Therefore, in 1967, the IOC created a medical commission (MC), which determines the list of drugs prohibited for use in sports and conducts anti-doping work, organizes and conducts doping control for the presence of prohibited drugs in the athlete’s body. Every athlete, coach, team doctor should know

prohibited drugs.

Classification doping

The means used in sports to enhance athletic performance include: doping agents, doping methods, psychological methods, mechanical factors, limited-use pharmacological agents, and nutritional supplements and substances.

Drugs that cause particular harm to health and are subject to control include doping and doping methods (manipulation).

According to their pharmacological action, dopings are divided into five classes: 1 - psychostimulants (amphetamine, ephedrine, phenamine, caffeine, cocaine, etc.); 2 - narcotic drugs (morphine, opiate alkaloids, promedol, fentanyl, etc.); 3 - anabolic steroids (testosterone and its derivatives, methane-drostenolone, retabolil, androdiol and many others), as well as anabolic peptide hormones (somatotropin, gonadotropin, erythropoietin); 4 - beta blockers (anaprimin (propranolol), oxprenolol, nadolol, atenolol, etc.); 5 - diuretics (novurit, dichlorothiazide, furosemide (Lasix), clopamide, diacarb, veroshpiron, etc.).

Dopings are biologically active substances isolated from animal or plant tissues and obtained synthetically, like their analogues. Many doping agents are included in medications for colds, flu and other illnesses, so an athlete's use of medications should be approved by a sports physician to avoid problems during doping control.

Doping methods include blood doping and various manipulations (for example, suppressing the ovulation process in women, etc.).

The biological effects of individual classes of doping in the body are varied. Thus, psychostimulants increase sports performance by activating the activity of the central nervous system, cardiovascular and respiratory systems, which improves the energy and contractile activity of skeletal muscles, and also relieve fatigue, give confidence in their abilities, but can lead to extreme strain on the functions of these systems and exhaustion of energy resources. Narcotic substances suppress pain sensitivity, as they are strong analgesics, and delay the feeling of fatigue. Anabolic steroids enhance the processes of protein synthesis and reduce their breakdown, therefore stimulating muscle growth and the number of red blood cells, helping to accelerate the body’s adaptation to muscle activity and recovery processes, and improve the composition of the body. Beta blockers counteract the effects of adrenaline and norepinephrine, which calms the athlete and increases adaptation to physical endurance exercise. Diuretics, or diuretics, enhance the removal of salts, water and some chemicals from the body, which helps to reduce body weight and remove illicit drugs.

It should be noted that among the classes of doping considered, anabolic steroids are most often used. In weightlifting, powerlifting, and bodybuilding, they are used by about 90% of men and 20% of women. In other sports they are used to a lesser extent (78% by football players, 40% by sprinters). In this case, the doses used can be many times higher than the recommended ones (5-10 mg) and reach 300 mg and even 2 g.

Tasks , objects And methods lopping control

The purpose of doping control is to identify the possible use of doping substances and doping methods by athletes at competitions and during training, and to apply special sanctions to those found guilty.

Doping control is carried out during the Olympic Games, World and European Championships, and more recently at smaller competitions or even during training (by decision of international sports organizations). Doping control is assigned by the medical commission of the IOC or NOC, and is carried out by special laboratories accredited by the IOC, usually from the country in which the competition is held. Doping laboratories exist at biochemical or other institutes equipped with modern equipment.

Recently, the main object of control has been used try urine, since it is a non-invasive object and an unlimited amount can be collected. The urine sample must be at least 100 ml with a pH of 6.5. Urine collection is carried out in the presence of an expert from the International Olympic Committee. The collected sample is divided into two parts and delivered in the cold to the doping control center.

Venous blood samples are used to detect blood doping.

To detect doping substances in the urine or blood of an athlete, highly sensitive methods of biochemical analysis are used, since the concentration of these substances is insignificant. These methods include: gas chromatography, masses- spectrometry, liquid chromatography, fluorescent immune analysis. In this case, at least two methods should be used.

Although doping control methods are highly sensitive, currently it is difficult to identify anabolic peptide hormones (somatotropin, erythropoietin, etc.), as well as the use of blood doping.

Literature:

1. Biochemistry: Textbook for institutes of physical culture / Ed. V.V. Menshikova, N.I. Volkova. - M.: Physical culture and sport, 1986. - 384 p.

2. Rogozkin V.A. Biochemical diagnostics in sports. – L.: Nauka, 1988. – 50 p.

3. Khmelevsky Yu.V., Usatenko O.K. Basic biochemical constants in normal and pathological conditions. – Kyiv: Health, 1984. – 120 p.

4. Physiological testing of high-class athletes / Ed. J. Duncan McDowell, Howard E. Wanger, Howard J. Green. – Kyiv: Olympic Literature, 1998. – 430 s.

5. N.I. Volkov, E.N. Nesen, A.A. Osipenko, S.N. Korsun, Olympic Literature, 2000. – 502 p.

Ministry of Education of the Republic of Belarus

Educational institution

MOGILEV STATE UNIVERSITY

NAMED AFTER A. A. KULESHOV

Department of Chemistry

Biochemistry of sports

Lectures on the course “Biochemistry of Sports”

For students of the Faculty of Physical Education

Mogilev 2007

BBK 28.072 ya73

UDC 577.12 (075.8)

Reviewed and approved at a meeting of the Department of Chemistry of Moscow State University. A. A. Kuleshova

Protocol No. 2007

Reviewers: Ustimenko A. N.

Filatov A. A.

The course of lectures is written in accordance with the approved curriculum for students of the Faculty of Physical Education. As a textbook, it represents the third section of the discipline “Biochemistry of Sports”. The third section is a special part of the discipline directly related to sports; students begin to master it after studying the sections of static and dynamic biochemistry.

Lecture No. 1

Adaptation theory and sports training

A person, whether he is an athlete, a businessman, or a musician, functions as a biological system according to the laws of nature.

Among the various types of human activity, sport occupies a special place and is an important and integral part of human culture.

If in ancient times sports were based on experience, intuition, and the excitement of competition, then modern scientific theory postulates that the objective basis of sport is biological law of adaptive change.

All living organisms, at least all known on Earth, have a vital quality - adaptability to influences, or more precisely, to changes affecting them, occurring in the environment. Adaptability differently the ability to adapt is a universal property of all living systems, allowing them to survive in constantly changing conditions and evolve. It should not be confused with addiction; it is also characteristic of living objects (many, including bipeds), but is the objective basis for the manifestation of addictions, especially negative ones.

The essence of the phenomenon of adaptation of living organisms is changes in biochemical processes, or biochemical changes in metabolism, actually induced, that is, caused by changes in environmental conditions (external or internal) environment. As a response of the body, they are aimed at establishing a new physiological state - homeostatic equilibrium, allowing a person to function normally in new changed conditions. Each new state is a new level of adaptability - adaptation to changed conditions, respectively, a level of fitness, according to the theory of sports.

The theory of adaptive changes considers changes in metabolism caused by sports physical activity as the theoretical biochemical basis of sports training. According to sports theory The training process is a process of directed, consciously controlled adaptation the body to specific, that is, determined by the characteristics of a particular sport, loads.

In relation to mass physical culture and sports, loads are determined by functional tasks - strengthening health, general physical condition, increasing the level of performance, endurance. For big sport and elite sport, the loads are competitive, maximum, often at the limit of human capabilities.

In sports, different goals and objectives are set depending on the level (reach of the masses or personal ambitions). Mass physical culture and sports are aimed at maintaining physical condition, as one of the main components of the health of each individual person (each of the “mass”), at an optimal level. Let us define the optimal level as everything that ensures survival in constantly changing conditions, maintains a high level of performance, and in general, contributes to positive evolutionary changes in the biological species Homo Sapiens and, of course, its progressive development.

The goals of big sport, sports of high achievements are theoretical - records and expanding the limits of physical, human capabilities, practical - records and victories - winning high prizes and awards in fair, sports competition, respectively.

Agree that achieving the goals of sports is impossible without knowledge and practical application of the laws of nature, which are studied by biology, physiology, anatomy, biochemistry and other sciences. In this regard, knowledge of the theory of adaptation and the biochemical foundations of training serves as a specific (by analogy with a computer) mental base of theoretical data, without which it is impossible to form a conscious attitude towards regular physical education for all those who are called the general population. For athletes involved in elite sports - high performance sports, the basis of the theory of adaptation and the biochemical foundations of training is the necessary minimum, allowing us to move from a conscious attitude to the training process to a theoretically based approach to it, to the scientific organization of sports training.

Let us generalize, both for the personality of a professional athlete and for an amateur athlete training is a process of consciously directed adaptation of the body to the effects of physical (and, or mental) stress, voluntarily assumed (in a sober mind and solid memory). The result of training is a new level of fitness and a new state of the athlete’s body, which is defined as sportswear (in this case we do not mean sportswear, of course).

Most specialists in the field of sports theory believe that

- Withathletic form is a strictly individual adaptive state of the body, which constantly changes in the process of sports improvement;

The natural, material basis of sports form is fitness, as a primary state formed during sports training.

Doctor of Pedagogical Sciences Ts. Zhelyazkov (National Academy of Sports, Sofia) emphasizes that “ “sports form can be formed as a qualitatively new state only and only on the basis of a high degree of training.”

Experts have made the following generalization of the essence of sports uniform:

The state of “sports form” is a natural result of training influences and associated adaptive changes in the body;

Training adaptation changes have a phase nature and are characterized by their quantitative and qualitative parameters;

Sports form can only arise with a stable state of general and special performance, defined as the fitness of the body;

Both states - fitness and sports form - are qualitatively different, regardless of their general nature;

Sports form is not a static state, but a state that develops over time, which, along with general features, also has its own specifics for various sports;

Sports form is the main constant factor for achieving high sports results.”

The concepts of fitness and sports form as states of an athlete have a common objective basis, since they are caused by the appearance sustainable adaptive changes in his body, however, they are not identical and in relation to the degree of optimal readiness to achieve high sports results are considered as two qualitatively different states of the body.

At the very initial stage of training (state 1 - the far right comrade in Fig. 1), one can hardly talk about the presence of sports form, as a state that ensures specific performance in a particular sport (or rather, sports form is zero). Agree that achieving sports results, even the most minimal ones (by this untrained subject) is a very unlikely event, although, in general, he is able to work (we believe that he is not sick).

Rice. 1. Change in training and acquisition of sports form during the training process.

Optimal (in terms of effectiveness) state of specific performance, in a specific sport, (state 5, Fig. 1) based on a high degree (level 5, Fig. 1) of training is necessary condition for acquisitions (not purchases) sports uniform, but not enough. In order to reach the state of the best sports form - readiness for the highest sports results, in addition to a high degree of training, a relatively stable component of the form, an optimal combination of a number of biosocial parameters (including psycho-emotional factors, motivation and others) is required. These parameters are labile - mobile and introduced from the external environment. In addition, we should not forget that readiness is not yet the actual achievement of a goal, it only creates the maximum probability (for example, an Olympic record). D. Zhelyazkov writes, “that the higher the athlete’s qualifications, the less time he needs to transition from a state of high fitness to a state of sports form.”

In recent years, the influence of biosocial parameters on the state of sports form has increased significantly. The commercialization of sports and aspects of prestige put the moral, volitional and emotional qualities of athletes to the test. “Failures” in sports form are often caused by the stressful influence of the social environment. Even a relatively stable component of fitness can simultaneously (and just at the “inopportune” moment - during competitions) be subject to psychoregulatory influence, that is, the influence of the labile component of sports form.

At the same time, experts point to the increasing “importance of positive emotions, conscious motivation and pre-start tuning of athletes and the ability of the coach (quite often his intuition) to guide them in the most correct way.” One cannot but agree with the conclusion made by Dr. Ts. Zhelyazkov in his article “On the Essence of Sports Form”: “the main criterion of sports form is high and stable sports results achieved in important competitions.”

In general, the complex of qualities of an athlete: his individual and genetic characteristics, personal characteristics, techniques and methods of the training process, lifestyle and nutrition, social, psycho-emotional and motivational aspects of training form the basis of sports form, the peak of which is so necessary to achieve the highest goals of sports - records and medals.

Description of presentation 1. Sports biochemistry evaluates the functional state of athletes using slides

1. Sports biochemistry evaluates the functional state of athletes during periods of performing training loads of various metabolic orientations. 2. How high is the probability that overwork is reliably present, or with what degree of reliability can this condition be excluded. 3. Unfortunately, the sensitivity and specificity of biochemical tests are not very high (about 70%).

Any physical work is accompanied by a change in the speed and direction of metabolic processes in the working muscles and throughout the body. The rate of catabolic processes accompanied by the release of energy (ATP resynthesis) increases. The rate of anabolic reactions (protein synthesis) decreases. This restructuring is controlled by the neurohumoral system. BIOCHEMICAL SHIFT IN THE BODY DURING PHYSICAL LOAD.

The tone of the sympathetic section of the ANS increases: 1. Pulmonary ventilation increases 2. Heart rate increases 3. Sweating increases, freeing the body from excess thermal energy 4. Blood supply to the kidneys decreases with a decrease in diuresis 5. Intestinal motility slows down with slower absorption of nutrients (this is why sports is needed . nutrition) 6. Fat is mobilized from the depot into the blood. Neurogenic regulation of physical activity:

1. The adrenal glands secrete catecholamines (adrenaline, norepinephrine). The biological effects of CA duplicate the action of sympathetic impulses. In addition, 2. adrenaline redistributes the blood: it dilates muscle vessels and constricts others (therefore, if an athlete’s face is red, this is bad). 3. Adrenaline stimulates the breakdown of liver glycogen to glucose, the so-called. emotional hyperglycemia, which begins even before the start. 4. Activates lipase, which leads to the breakdown of fat into glycerol and fatty acids (a source of energy), in the liver glucose is synthesized from glycerol, and ketone bodies from fatty acids. 5. In muscle tissue, under the influence of adrenaline, free glucose is not formed from glycogen. Depending on the direction of work, glycogen is converted either into lactic acid (glycolysis) or into carbon dioxide and water (oxidation). Hormonal regulation:

1. The adrenal cortex produces steroid hormones - corticosteroids, which, according to their biological action, are divided into glucocorticoids (cortisol, cortisone, corticosterone) and mineralocorticoids (aldosterone). 2. Biological effect of glucocorticoids: 3. Anabolic processes (protein synthesis) slow down. 4. They inhibit the use of glucose by the body’s cells, which leads to its accumulation in the blood. 5. Stimulate gluconeogenesis (in the liver) – synthesis of glucose from non-carbohydrates (amino acids, glycerol, lactic acid) Hormonal regulation

1. Sympathicotonia - the mechanism works mainly in an aerobic mode (weight loss due to fat). 2. Catecholamines: aerobic mode + PANO 3. Corticosteroids: anaerobic mode (suppression of SAS). Losing weight through muscles! Example: athlete B. During his vacation, he gained up to 6-8 kg of fat, lost weight on glycolysis in 3-4 weeks. I lost both fat and muscle. Unbalanced the hormonal system.

The depth of biochemical changes in the blood depends on the power and duration of physical activity. Having reached a certain level, biochemical changes begin to negatively affect performance.

1. The breakdown of creatine phosphate into creatine and phosphoric acid. 2. Reduction of glycogen, regardless of the energy orientation of physical work. During intensive work, a rapid decrease in glycogen reserves (30-60 minutes) and accumulation of lactate are observed. Lactate in the muscles leads to an increase in osmotic pressure in them, as a result of which water enters the myocytes from the capillaries and the muscles swell (“muscle congestion”). 3. At low work intensity, glycogen breaks down aerobically with the formation of carbon dioxide and water (oxidation). 4. The breakdown of muscle proteins leads to the formation of ammonia, which in the liver is converted into urea, which is not toxic but requires a significant amount of energy (the muscles and the synthetic function of the liver lack it). Biochemical changes in muscles during physical activity:

1. The number and volume of myocyte mitochondria increases 2. The content of HB in the blood (erythropoietin) increases. 3. Cardio-respiratory indicators improve (morning pulse, optimal blood pressure - increase in pulse blood pressure) 4. Feritin levels decrease and transferrin levels increase. 5. Microcirculation improves. 6. The level of LPO in the blood increases. 7. The content of triglycerides and fatty acids in the blood increases. 8. Low lactate during standard aerobic exercise. Effect of aerobic training: (resynthesis of ATP in mitochondria)

1. This reaction is catalyzed by creatine kinase (CK), therefore this pathway is also called creatine kinase. 2. Total reserves of ATP and creatine phosphate (phosphagens). Creatine is formed in the liver using three amino acids: glycine, methionine, arginine. 3. Heptral (activated methionine) is a kind of substrate for creatine phosphate. Creatine phosphate pathway for ATP resynthesis (alactate).

1. The source of energy (substrate) is muscle glycogen located in the sarcoplasm of the myocyte and blood glucose. The catalyst is adrenaline. 2. Glucose: food, glycolysis in the liver (adrenaline), gluconeogenesis in the liver (glucocorticoids). Glycolytic pathway for ATP resynthesis

1. Increase in glycogen concentration 2. Increase in the activity of glycolytic enzymes (lactate dehydrogenase, phosphorylase, phosphofructogenase). 3. Resistance of tissues to a decrease in r. H (highly trained athletes easily tolerate pH 7 or less). 4. A decrease in insulin in the blood is a sign of a lack of muscle glycogen. 5. An increase in glycolytic (lactate) energy production is evidenced by a later achievement of the maximum amount of lactate in the blood during extreme physical activity, and its higher level. Effect of glycolytic training:

1. The biochemical changes that occur after performing a standard load are usually greater, the lower the level of training. 2. A significant increase in lactate after a standard load indicates low aerobic energy production capabilities. 3. A decrease in lactate at different stages of training during standard work indicates the effectiveness of the training process. BIOCHEMICAL CONTROL OF THE DEGREE OF FITNESS OF AN ATHLETE (by lactate).

1. 1st – lactate content is increased, the lactate/pyruvate ratio is normal, there is no pronounced acidosis (compensated acidosis); 2. 2nd – lactate content is increased, L\P is increased, pronounced acidosis is characteristic (uncompensated acidosis). 3. The maximum lactate during a load “to failure” is used to judge the glycolytic capacity (power). Types of lactic acidosis in the blood:

Cellular enzymes (indicator): CPK, LDH, AST An increase in indicator enzymes in the blood and their isoforms indicates damage to muscle cell membranes. As a result, myoglobin and tropomyosin are released into the blood. Enzymes for the biological oxidation of substances: aldolase (glycolysis enzyme), catalase (hydrogen peroxide reduction enzyme), superoxide dismutase (antioxidant protection against free radicals). ENZYMES (Metabolic regulators)

About 20 hormones that regulate metabolism can be detected in the blood. Hormonal profile is an indicator of hidden disorders in the adaptation process. Cortisol. Increasing it is the body’s reaction to stress (physical, psychological). Long-term persistence of elevated cortisol levels (oxidative stress) can lead to muscle tissue wasting, as well as arterial hypertension, gastrointestinal ulcers, thyroid dysfunction, immunodeficiency, sleep disturbances, and hyperglycemia. Hormones

1. Hormones of the sympathoadrenal system (adrenaline, norepinephrine, serotonin). When physical activity is inadequate to the functional state, an increase in its level indicates the exhaustion of the biosynthetic reserves of the endocrine glands. 2. Growth hormone (somatotropin), insulin-like growth factor (somatomedin C): increased protein synthesis. Intense physical activity leads to a decrease in hormones, aerobic work increases its level. Hormones

1. Insulin. Its role is to increase tissue glucose consumption and, as a result, reduce blood glucose levels. 2. A decrease in the level of insulin in the blood occurs after 15-20 minutes of muscle work. After completing the load the next day, its level decreases (indirectly indicating glycogen deficiency). 3. Testosterone. Has an anabolic effect on muscle tissue. Exhausting long-term physical activity, as well as inactivity, reduce testosterone. Hormones

Approximately 2% of testosterone circulating in the blood is in a free state. Determination of free testosterone is indicated when the level of SHBG (sex hormone binding globulin) is increased (hyperthyroidism, hyperestrogenism, taking oral contraceptives) or decreased (hypothyroidism, obesity). Hormones

Initially, cortisone was persistently elevated (tall, asthenic young girls under 18 years old): problem of hormone metabolism in adipose tissue: St. testosterone, SHBG, estrogens, aromatase, IPFR, myostatin. Persistent increase in cortisol during training: 1. Cytokine inflammation (TNF, interleukins) or infection. 2. Water-electrolyte substances: sodium, potassium, zinc 3. Depletion of muscle glycogen (insulin, ammonia, urea) 4. Superoxide radicals (superoxide dismutase) Hypercortisolism

1. Inorganic phosphorus is formed in muscles during the creatine phosphate pathway of ATP resynthesis. The higher it is during anaerobic exercise, the higher the level of fitness. 2. Potassium is the most important activator of a number of enzymes. Potassium deficiency is caused by physical and mental stress (cortisol), sweating. Minerals

1. Calcium - found in bones. 1% in ionized form in the blood, participating in neuromuscular conduction and blood clotting. With deficiency: mental anxiety, insomnia, headache. 2. Zinc is necessary for protein synthesis, digestive enzymes, superoxide dismutase, and insulin. 3. Magnesium – together with potassium, the main intracellular element. A deficiency of magnesium in the blood is a sign of overtraining. Minerals

1. Physical activity during the training process is performed when fatigue from previous loads has not yet passed and fatigue is added up (cumulate). Fatigue becomes chronic. This is called overwork. 2. Cumulative fatigue is called overtraining or overtraining. In English-language literature - overtraining syndrome. Fatigue and overtraining

1. Fatigue during physical work of moderate power (pathway - aerobic oxidation, time - over 30 minutes). 2. Decomposition products are completely recycled. With prolonged work in this range, hypoglycemia occurs. (depletion of carbohydrate resources of muscles and liver). The central nervous system is especially sensitive to a lack of carbohydrates: loss of coordination, inappropriate behavior. In addition to hypoglycemia, during prolonged work in this range, thermoregulation is disrupted (more heat is produced than is given off), hence overheating, especially with high humidity. Violation of water-salt balance (hyponatremia, hypovolemia). Accumulation of under-oxidized products of fat metabolism (ketone bodies). Physiological factors in the development of fatigue (urgent, operational changes)

1. Fatigue during cyclic work of high power (aerobic oxidation + glycolysis), time – up to 30 minutes). 2. Oxygen debt is steadily increasing. The result is the accumulation of under-oxidized products in the blood (lactate, LPO, free radicals). Depletion of either phosphagens or muscle glycogen. Depletion of the functional reserve of the heart. Thermoregulation voltage and r. N.

1. Fatigue during cyclic work of maximum (15-20 sec, creatine phosphate mechanism) and submaximal (up to 5 minutes, glycolytic) power. 2. inhibition of the central nervous system centers, hence muscle movements are constrained, the function of the cardiovascular and respiratory systems decreases. 3. High level of lactic acid, hence the speed of muscle contraction decreases (shortening the step). Decrease (depletion) of CP and glycogen reserves. Violation of CBS; inhibition of the activity of glycolysis and glycogenolysis enzymes;

1. In acute fatigue, myogenic leukocytosis with phase changes appears. In the first hours after exercise. 2. Leukocytosis, absolute and relative lymphocytosis, absolute and relative neutropenia, eosinopenia, basophilopenia. Then a rod shift to the left. 3. After a day, normalization of leukocytes without normalization of the formula. 4. After 3-4 days: leukopenia with lymphocytosis. 5. In case of exhaustion: neutropenia with lymphocytosis, thrombocytopenia. 6. ESR: does not change with adequate loads. In case of inadequate increase in ESR. 7. Tendency to increase hematocrit (with overtraining, Hb decreases, Ht increases). Hematological parameters for fatigue

With the development of fatigue, all hormones in the blood increase, except insulin and estradiol. With overtraining, everything decreases. The reaction of the endocrine system to fatigue is diagnosed: High levels of cortisol after physical activity and slow recovery; Decrease in testosterone and testosterone\cortisol index, lack of recovery within 3 days; Decreased insulin after exercise and lack of recovery during the day (decreased muscle glycogen); Decrease in somatomedin C and lack of recovery within 3 days; Decreased potassium in the blood (increased aldosterone) and lack of its recovery during the day; Hormonal profile indicators for fatigue

1. A long-term decrease in glycogen levels leads to increased breakdown of branched chain amino acids (BCAAs) in muscles. Hence the urea. 2. The appearance of glucose in the urine is a sign of intensive mobilization of liver glycogen. 3. Urea. The main biochemical indicator of the body’s recovery after physical activity. Determine on an empty stomach the day after exercise, or after a day of rest. It must be taken into account that when taking amino acids, urea levels in the blood are adjusted upward (by 1 -1.5 mmol/l). Norms: for men – 6.6 mmol/l, for women 5 mmol/l.

1. The urea test does not exceed the norm for two days in a row. This is a balance between the processes of catabolism and anabolism. 2. A further increase in loads leads to a decrease in urea (sometimes even below the population norm). This is a sign of under-recovery. The athlete complains of difficulties in performing high-speed loads. 3. Urea is elevated for two days in a row and tends to increase. This is observed after high-intensity, stressful loads. This type of reaction indicates a discrepancy between the body’s functional capabilities and training loads. Based on the urea content, the types of athlete’s reactions to loads are determined:

When muscle glycogen is depleted, the catabolism of the protein structures of the myocyte increases with the formation of ammonia. Ammonia blocks the release of lactate from the muscle cell and the process of aerobic phosphorylation (stops the aerobic use of pyruvate). This is the so-called “metabolic death”. Ammonia stimulates hyperpnea (shortness of breath), (increased carbon dioxide in the blood). Increased catabolism of muscle proteins can be measured in the blood, saliva, and urinary excretion of 3-methyl-histidine, a specific metabolite of muscle proteins. Ammonia

1. The hemostatic system is the most sensitive to any disturbances in the body. 2. The coefficient of microcirculation (CM), equal to the biological age of the athlete, is calculated by the formula: 3. CM=7.546 x. Fg-039 x. Tr-0, 381 x. APTT+0.234 x. FA+0, 321 x. RFMK-0, 664 x AT 111+101, 064 4. Where-Fg - fibrinogen (g/l); Tp - platelets (10 in 9 st/l); APTT—activated partial thromboplastin time (s); FA—fibrinolytic activity (min); RFMC - soluble fibrin monomer complexes (mg/ml); AT 111 - antithrombin 111(%). 5. The lack of recovery of CM on the 3rd day of rest indicates a pronounced development of fatigue in the athlete. Indicators of the coagulation system

Recovery is assessed by the content of metabolites of carbohydrate, protein and fat metabolism in the blood or urine. Carbohydrate metabolism - the rate of lactate utilization. Lipid metabolism – increase in fatty acids and utilization of ketone bodies. Protein metabolism - the rate of urea utilization. Biochemical tests for fatigue are carried out during the training period and at its end, or the next morning on an empty stomach. Recovery studies are usually performed after a day of rest. Restoration of the body

1. Based on measuring the activity of sarcoplasmic enzymes (CPK, LDH, AST) in the blood. When working in the gym, these enzymes can increase significantly (CPK up to 2000 units) due to the rupture of short myofibrils (the cycle does not need them) and plus creatine phosphate work (indirectly indicates a decrease in CP reserves). 2. With any increase in CPK, it is necessary to exclude pathology of the heart (myocardium): CPK MV (no more than 10-12%), troponin, ECG. It is better to study CPK MM - a specific enzyme of peripheral muscles. In case of muscle overstrain, it is better to use a diagnostic combination: An increase in CPK and malondialdehyde is a sure sign of muscle overstrain. Overstrain of muscle tissue

1. Long-term high levels of CPK, AST, LDH; 2. Long-term high levels of myoglobin; 3. Detection of troponin and actin in the blood; 4. High levels of malondialdehyde LPO), molecules of average mass (endogenous intoxication); 5. Reduced superoxide dismutase activity; 6. High levels in the blood, saliva, urine of creatine 7. and 3-methylhistidine; Biochemical markers of muscle tissue overstrain (damage)

1. Serum iron. An unreliable indicator when examining a finger prick (hemolysis), in addition, with any inflammation (cytokine inflammation), iron from the blood is deposited in the liver. 2. Feritin. A marker for assessing iron reserves in the body. It is unreliable, since with any inflammation (and at the height of intense loads, cytokine inflammation is observed in all athletes), it increases, and with aerobic exercise it decreases. 3. Transferrin saturation is a marker of iron deficiency. With iron deficiency it decreases. Unreliable for the same reason. 4. Transferrin receptor (s. Tf. R). Reflects the ineffectiveness of erythropoiesis. A more accurate indicator is the ratio s. Tf. R\logarithm of feritin. An increase in this index means iron deficiency. Determination of iron deficiency

The hemoglobin content in the reticulocyte is the most accurate indicator of iron deficiency. (it is also possible in an erythrocyte, but this is less accurate) A hematology analyzer of the ADVIA line is used, the indicator is designated as CHr. Currently, SISMEX analyzers of the XT and XE lines are used, the RET indicator is H e.

1. Goal: to evaluate long-term adaptation 2. General clinical blood test on a SISMEX analyzer (preferably on SISMEX lines CT and XE). 3. General urine analysis (pH, density, ketones, salts, protein, glucose). 4. Microcirculation (fibrinogen, antithrombin 111, APTT, fibrin-monomer complexes, D-dimer, fibrinolytic activity, microcirculation coefficient). 5. Biochemical profile (glucose, LDH, urea, uric acid, creatinine, CPK, ALT, AST, albumin (prealbumin), globulin, medium-weight molecules, potassium, magnesium, sodium, ionized calcium, zinc. 6. Hormonal profile (TSH , testosterone, cortisol, SHBG, insulin, somatomedin-C, myostatin).A staged comprehensive examination is carried out 2-3 times a year

1. Oxidant status (malondialdehyde, superoxide dismutase). 2. Diagnosis of iron deficiency and vitamin B 12 deficiency (based on the results of Sysmex indicators: vitamin B 12 and folic acid by the size of the red blood cell, iron deficiency by the saturation of the reticulocyte with hemoglobin). 3. Level of basic amino acids in the blood (isoleucine, valine, etc.) 4. Vitamin D (or its metabolite (25 OH vitamin D) in the blood 5. Immune status and interferon status to identify damaged immunity, selection of corrective immunomodulatory therapy. 6. Mediators of cytokine inflammation: tumor necrosis factor (TNF), interleukins. IVF

1. It is usually carried out weekly during training. It is carried out to assess operational adaptation to loads. 2. The degree of fitness can be assessed by biochemical indicators only when using standard physical activity (usually at the level of PANO). 3. Recovery (overtraining) – after a day of rest. CURRENT CHECK-UP (TO)

1. General clinical blood test on a hematology analyzer. 2. Biochemical analysis: CBS, glucose, lactate, urea, uric acid, creatinine, CPK, AST, ALT, magnesium, ionized calcium, potassium, sodium, zinc. 3. Hormonal status: testosterone, cortisol, SHBG, insulin. 4. Oxidant status: malondialdehyde, superoxide dismutase. Basic panel

Aerobic pathway of ATP resynthesis (efficiency): 1. Assessment of the oxygen transport system of the blood (general clinical blood test). 2. Assessment of microcirculation by microcirculation coefficient). 3. LPO products in the blood (malondialdehyde) – increase. 4. Triglycerides and fatty acids in the blood - increase 5. Ketone bodies - increase. 6. Lactate during standard aerobic exercise is low. 7. Ferritin (slight decrease), transferrin (slight increase) 8. Superoxide dismutase (SOD) - decrease. Energy panel:

1. Creatinine, creatine, CPK, phosphorus in the blood and urine - increase. 2. Creatinine coefficient is the excretion of creatinine in urine per day per 1 kg of weight. The norm for men is 18-32 mg/day-kg, for women 10-25 mg/day-kg (metabolic capacity of creatine phosphate). Creatine phosphate pathway for ATP resynthesis:

1. Lactate and r. H at maximum work (metabolic capacity of glycolysis). 2. Urine (preferably daily) for lactate and p. H (total contribution of the glycolytic pathway of ATP resynthesis). 3. Lactate dehydrogenase, phosphorylase, phosphofructogenase. Increased activity of glycolytic enzymes. 4. Insulin in the blood – decrease. Glycolytic pathway of ATP resynthesis (efficiency):

1. Increase growth hormone (somatomedin C, IPFR 1) by adequate physical activity, arginine, vitamin PP, insulin, fasting. 2. STH is reduced by physical inactivity, obesity, carbohydrates, and hypercortisolism. 3. For high urea carbohydrates, high-insulin polysaccharides are best. Carbohydrates will not lower urea if blood insulin is low.

According to recent data (2007), vitamin D has moved beyond calcium metabolism and has become a biological inhibitor of inflammation (through the suppression of the inflammatory cytokine interleukin 2). Vitamin D (hormone D)

1. vague symptoms (discomfort) 2. constant nonspecific musculoskeletal pain 3. Muscle weakness. Symptoms of Vitamin D Deficiency

1. There is a control system in muscle cells. Muscle growth factor IGF-1 (insulin-like growth factor, IGF) stimulates muscle growth, and myostatin (growth differentiation factor 8) suppresses it. 2. A group of scientists in Pittsburgh (Canada) found that resistance training suppresses the activity of myostatin. It should be noted that both IGF and myostatin are synthesized in adipose tissue. MYOSTATIN

1. In humans, myostatin is encoded in the MSTH gene. 2. Development of myostatin inhibitors is underway, but currently there is not a single effective and safe drug. 3. There is evidence that creatine suppresses myostatin.

1. Malondialdehyde (MDA): a marker of LPO (products of lipid peroxidation), which arise under the influence of superoxide radicals. Reduce oxygen utilization by muscles. An indicator of oxidative stress. 2. Medium molecules: markers of the degree of catabolism 3. Superoxide dismutase: metalloenzyme that utilizes oxygen. Neutralizes reactive oxygen species.

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College of Physical Education

LECTURE COURSE

BASICS OF SPORTS BIOCHEMISTRY

Kucheryavyi Vsevolod Vladimirovich

Topic 1. Structure of proteins and enzymatic catalysis.

Topic 6. Protein metabolism

SECTION 3. WATER-MINERAL METABOLISM. VITAMINS. HORMONES

Topic 7. Exchange of water and salts. Vitamins

Topic 8. Hormones, biochemistry of urine and blood

PART 2. BASICS OF SPORTS BIOCHEMISTRY

SECTION 4. BIOCHEMISTRY OF MUSCLE ACTIVITY

Topic 9. Biochemistry of muscle contraction

Topic 10. Energy supply of muscle contraction

SECTION 5. GENERAL BIOCHEMISTRY OF SPORTS ACTIVITY

Topic 11. Biochemical changes during muscle work

Topic 12. Biochemical mechanisms of fatigue

Topic 13. Recovery from a biochemical point of view

Topic 14. General biochemical patterns of adaptation to muscular work

SECTION 6. SPORTS PERFORMANCE AND BIOCHEMISTRY

Topic 15. Biochemical basis of performance

Topic 16. Biochemical methods of increasing performance

APPENDIX 1. Biochemistry exam questions

PART 1. BASICS OF GENERAL BIOCHEMISTRY

SECTION 1. GENERAL CHARACTERISTICS OF METABOLISM

Topic 1. Protein structure and enzymatic catalysis

1. Biological role of proteins

2. Structure of a protein molecule

3. Classification of proteins

5. Structure of enzymes

Introduction. What does biochemistry do?

Biochemistry studies the chemical processes occurring in living systems. In other words, biochemistry studies the chemistry of life. This science is relatively young. She was born in the 20th century. Conventionally, the biochemistry course can be divided into three parts.

General biochemistry deals with the general laws of the chemical composition and metabolism of various living beings, from the smallest microorganisms to humans. It turned out that these patterns are largely repeated.

Particular biochemistry deals with the peculiarities of chemical processes occurring in certain groups of living beings. For example, biochemical processes in plants, animals, fungi and microorganisms have their own characteristics, and in some cases very significant ones.

Functional biochemistry deals with the peculiarities of biochemical processes occurring in individual organisms associated with the characteristics of their lifestyle. The direction of functional biochemistry that studies the effect of physical exercise on the athlete’s body is called sports biochemistry or sports biochemistry.

The development of physical culture and sports requires athletes and coaches to have good knowledge in the field of biochemistry. This is due to the fact that without understanding how the body works at the chemical, molecular level, it is difficult to hope for success in modern sports. Many training and recovery techniques these days are based on a deep understanding of how the body works at the subcellular and molecular level. Without a deep understanding of biochemical processes, it is impossible to fight doping - an evil that can ruin sports.

1. Biological role of proteins

The role of proteins in the body is difficult to overestimate. That is why our course begins with a description of the role and structure of this particular class of bioorganic compounds. Proteins in the body perform the following functions.

1. Structural or plastic function. Proteins are a universal building material from which almost all structures of living cells are composed. For example, in the human body, proteins make up about 1/6 of body weight. Moreover, in trained people with well-developed muscles, this figure may be higher.

2. Catalytic function. Many proteins, called enzymes or enzymes, perform the function of catalysts in living systems, that is, they change the rate of chemical reactions (which will be discussed in detail below)

3. Contractile function. It is protein molecules that underlie all forms of movement of living systems. Muscle contraction is primarily the work of proteins.

4. Regulatory function. This function is based on the ability of protein molecules to react with both acids and bases, called amphotericity in chemistry. Proteins are involved in creating homeostasis in the body. Many proteins are hormones.

5. Receptor function. This function is based on the ability of proteins to respond to emerging changes in the conditions of the internal environment of the body. Various receptors in the body that are sensitive to temperature, pressure, and light are proteins. Hormone receptors are also proteins.

6. Transport function. Protein molecules are large in size and highly soluble in water, which allows them to easily move through aqueous solutions and transport various substances. For example, hemoglobin transports gases, blood albumins transport fats and fatty acids.

7. Protective function. Proteins protect the body, first of all, by participating in the creation of immunity.

8. Energy function. Proteins are not the main participants in energy metabolism, but they still provide up to 10% of the body’s daily energy needs. At the same time, it is too valuable a product to be used as an energy source. Therefore, proteins are used as a source of energy only after carbohydrates and fats.

2. Structure of a protein molecule

Proteins are high molecular weight nitrogen-containing compounds consisting of amino acids. Proteins contain hundreds of amino acid residues. However, all proteins, regardless of origin, are formed by 20 types of amino acids. These 20 amino acids are therefore called proteinogenic.

Amino acids contain a carboxyl group COOH and an amino group NH2. True, some proteins still contain very small amounts of amino acids that are not part of the proteinogenic ones. Such amino acids are called minor. They are formed from proteinogenic amino acids after the completion of the synthesis of protein molecules.

Amino acids are connected to each other by peptide bonds, forming long unbranched chains - polypeptides. A peptide bond occurs when the carboxyl group of one amino acid interacts with the amino group of another, releasing water. Peptide bonds are highly durable and are formed by all amino acids. It is these bonds that form the first level of organization of the protein molecule - the primary structure of the protein. Primary structure is the sequence of amino acid residues in the polypeptide chain of a protein.

The secondary structure of the protein is a helical structure formed mainly by hydrogen bonds.

The tertiary structure of a protein is a globule or ball into which the secondary helix in some proteins folds. Various intermolecular forces, primarily disulfide bridges, participate in the formation of a globule. Since disulfide bonds are formed by amino acids that contain sulfur, globular proteins usually contain a lot of sulfur.

Some proteins form a quaternary structure consisting of several globules, then called subunits. For example, the hemoglobin molecule consists of four subunits that perform a single function.

All structural levels of a protein molecule depend on the primary structure. Changes in the primary structure lead to changes at other levels of protein organization.

3. Classification of proteins

The classification of proteins is based on their chemical composition. According to this classification, proteins are divided into simple and complex. Simple proteins consist only of amino acids, that is, of one or more polypeptides. Simple proteins found in the human body include albumins, globulins, histones, and supporting tissue proteins.

In a complex protein molecule, in addition to amino acids, there is also a non-amino acid part, called a prosthetic group. Depending on the structure of this group, complex proteins are distinguished such as phosphoproteins (contain phosphoric acid), nucleoproteins (contain nucleic acid), glycoproteins (contain carbohydrates), lipoproteins (contain lipoid) and others.

According to the classification, which is based on the spatial shape of proteins, proteins are divided into fibrillar and globular.

Fibrillar proteins consist of helices, that is, predominantly of secondary structure. Molecules of globular proteins have a spherical and ellipsoidal shape.

An example of fibrillar proteins is collagen, the most abundant protein in the human body. This protein accounts for 25 - 30% of the total number of proteins in the body. Collagen has high strength and elasticity. It is part of the blood vessels of muscles, tendons, cartilage, bones, and vessel walls.

An example of globular proteins are albumins and globulins in blood plasma.

4. Physicochemical properties of proteins

One of the main features of proteins is their large molecular weight, which ranges from 6000 to several million daltons.

Another important physicochemical property of proteins is their amphotericity, that is, the presence of both acidic and basic properties. Amphotericity is associated with the presence in some amino acids of free carboxyl groups, that is, acidic, and amino groups, that is, alkaline. This leads to the fact that in an acidic environment proteins exhibit alkaline properties, and in an alkaline environment - acidic. However, under certain conditions, proteins exhibit neutral properties. The pH value at which proteins exhibit neutral properties is called the isoelectric point. The isoelectric point for each protein is individual. Proteins according to this indicator are divided into two large classes - acidic and alkaline, since the isoelectric point can be shifted either in one direction or the other.

Another important property of protein molecules is solubility. Despite the large size of the molecules, proteins are quite soluble in water. Moreover, solutions of proteins in water are very stable. The first reason for the solubility of proteins is the presence of a charge on the surface of protein molecules, due to which protein molecules practically do not form aggregates that are insoluble in water. The second reason for the stability of protein solutions is the presence of a hydration (water) shell in the protein molecule. The hydration shell separates the proteins from each other.

The third important physicochemical property of proteins is salting out, that is, the ability to precipitate under the influence of water-removing agents. Salting out is a reversible process. This ability to move in and out of solution is very important for the manifestation of many vital properties.

Finally, the most important property of proteins is their ability to denature. Denaturation is the loss of nativeness by a protein. When we scramble eggs in a frying pan, we get irreversible denaturation of the protein. Denaturation consists of permanent or temporary disruption of the secondary and tertiary structure of a protein, but the primary structure is preserved. In addition to temperature (above 50 degrees), denaturation can be caused by other physical factors: radiation, ultrasound, vibration, strong acids and alkalis. Denaturation can be reversible or irreversible. With small impacts, the destruction of the secondary and tertiary structures of the protein occurs insignificantly. Therefore, in the absence of a denaturing agent, the protein can restore its native structure. The reverse process of denaturation is called renaturation. However, with prolonged and strong exposure, renaturation becomes impossible, and denaturation is thus irreversible.

5. Structure of enzymes

Enzymes or enzymes are proteins that perform catalytic functions in the body. Catalysis involves both speeding up and slowing down chemical reactions.

Enzymes almost always speed up chemical reactions in the body, and they speed up tens and hundreds of times. In other reactions that take place under the control of enzymes, the rate in their absence drops to almost zero.

The region of the enzyme that is directly involved in catalysis is called the active site. It can be organized differently in enzymes that have only tertiary and quaternary structure. In complex proteins, as a rule, all subunits, as well as their prosthetic groups, participate in the formation of the active center.

There are two sections in the active center - adsorption and catalytic.

The adsorption site is the binding site. Its structure corresponds to the structure of reacting substances, called substrates in biochemistry. They say that the substrates and the adsorption site of the enzyme coincide like a key and a lock. Most enzymes have one active site, but there are enzymes that have multiple active sites.

It must be said that not only the active center of the enzyme, but also its other parts take part in the enzymatic reaction. The overall conformation of the enzyme plays an important role in its activity. Therefore, changing even one amino acid in a part of the molecule that is not directly related to the active center can greatly affect the activity of the enzyme and even reduce it to zero. Thanks to a change in the conformation of the enzyme, its active center “adapts” to the structure of the substrates participating in the reaction accelerated by the enzyme.

6. Mechanism of action of enzymes. Specificity

It must be remembered that when performing a catalytic function, the catalyst itself does not change its chemical nature. This statement is also true for enzymes.

In any catalytic reaction carried out by enzymes, there are three stages.

1. Formation of an enzyme-substrate complex. At this stage, the active center of the enzyme binds to substrates through weak bonds, usually hydrogen bonds. A feature of this stage is complete reversibility, since the enzyme-substrate complex can easily decompose into enzyme and substrates. At this stage, a favorable orientation of the substrate molecules occurs, which accelerates their interaction.

2. This stage takes place with the participation of the catalytic site of the active center. The essence of this stage is to reduce the activation energy and accelerate the reaction between substrates. The result of this stage is the formation of a new product.

3. At this stage, the finished product is separated from the active center, releasing the enzyme, which is again ready to carry out its function.

In cells, enzymes that catalyze multistage processes are often combined into complexes called multienzyme systems. Most often, these complexes are embedded in biomembranes or associated with cell organelles. This combination of enzymes makes their work more efficient.

In some cases, enzyme proteins contain non-protein components involved in catalysis. Such non-protein elements are called coenzymes. Most coenzymes contain vitamins.

The most important property of enzymes is their high specificity. In biochemistry there is a rule: one reaction - one enzyme. There are two types of specificity: action specificity and substrate specificity.

Specificity of action is the ability of an enzyme to catalyze only one specific type of chemical reaction. If a substrate can undergo various reactions, then each reaction requires its own enzyme.

Substrate specificity is the ability of an enzyme to act only on certain substrates.

Substrate specificity can be absolute or relative.

With absolute specificity, the enzyme catalyzes the transformation of only one substrate.

When relative, there may be a group of similar substrates.

7. What does the speed of enzymatic reactions depend on?

Chemical reactions are based on activation energy. If the activation energy is high, then the substances cannot react or the rate of their interaction will be low. Enzymes lower the activation energy threshold.

The speed of enzymatic reactions depends significantly on many factors. These include the concentrations of substances participating in the enzymatic reaction, as well as the environmental conditions in which the reaction occurs.

It has been shown that the higher the enzyme concentration, the higher the reaction rate. This is because the enzyme concentration is much lower than the substrate concentration.

At low substrate concentrations, the rate of reaction is directly proportional to the concentration of substrates. However, as the concentration of the substrate increases, it begins to slow down and, finally, having reached its maximum speed, it stops growing. This is because as the substrate concentration increases, the amount of free active cents becomes the limiting factor.

Temperature affects enzymatic reactions in a unique way. The fact is that enzymes are proteins, which means that at high temperatures (above 80 degrees), they completely lose activity. Therefore, for enzymatic reactions there is the concept of a temperature optimum. The optimum for most enzymes is a body temperature of 37 - 40 degrees. At low temperatures, enzymes are also inactive.

Another factor determining enzyme activity is the pH of the environment. Here, each enzyme has its own pH optimum. For example, gastric juice enzymes have a pH optimum in an acidic environment (pH - 1.0 to 2.0), and pancreatic enzymes prefer an alkaline environment (pH - 9.0 - 10.0).

In addition to the above factors, various substances - inhibitors and activators - affect the rate of enzymatic reactions.

Inhibitors are, most often, low molecular weight substances that slow down the reaction rate. The inhibitor binds to the enzyme, preventing it from performing its function.

Activators are substances that selectively increase the rate of enzymatic reactions.

Hormones can act as both activators and inhibitors of enzymes.

The speed of enzymatic reactions depends on a number of other factors:

· changes in the rate of enzyme synthesis;

· . enzyme modifications;

· change in enzyme conformation

8. Classification and nomenclature of enzymes

The modern classification of enzymes is based on the characteristics of the chemical reaction catalyzed by the enzyme. There are six main classes of enzymes.

1. Oxidoreductases are enzymes that catalyze redox reactions. Schematically it looks like this:

2. Transferases - enzymes that catalyze the transfer of chemical groups from one molecule to another

AB + C > A + BC

3. Hydrolases are enzymes that break down chemical bonds by adding water, that is, hydrolysis.

AB + H2O >A - H + B - OH

4. Lyases - enzymes that catalyze the cleavage of chemical bonds without adding water:

5. Isomerases are enzymes that catalyze isomeric transformations, that is, the transfer of individual chemical groups within one molecule:

6. Synthetases are enzymes that catalyze synthesis reactions that occur using the energy of ATP:

ATP + H2O > ADP + H3PO4

Each class is in turn divided into subclasses, and those into subsubclasses.

The name of the enzyme usually consists of two parts. The first part reflects the name of the substrate, the transformation of which is catalyzed by this enzyme. The second part of the name has the ending “-aza”, indicating the nature of the reaction. For example, an enzyme that removes hydrogen atoms from lactic acid (lactate) is called lactate dehydrogenase. And the enzyme that catalyzes the isomerization of glucose-6-phosphate into fructose-6-phosphate is called glucose phosphate isomerase. The enzyme involved in glycogen synthesis is called glycogen synthetase.

Topic 2. Metabolic stages and biological oxidation

3. Tissue respiration

1. General characteristics of metabolism

Metabolism and energy are a prerequisite for the existence of living organisms.

The body receives energy and building substances from the external environment, then these substances are processed and, finally, unnecessary waste products are released from the body into the environment. Thus, metabolism can be represented as three processes.

1. Digestion is a process during which food substances, usually high-molecular and foreign to the body, are broken down under the action of digestive enzymes and converted into simple compounds - universal for all living organisms. Proteins, for example, break down into amino acids exactly the same as the amino acids of the body itself. The universal monosaccharide glucose is formed from food carbohydrates. Therefore, the final products of digestion can be introduced into the internal environment of the body and used by cells for a variety of purposes.

2. Metabolism is a set of chemical reactions occurring in the internal environment of the body. True, sometimes the word “metabolism” is understood as a synonym for metabolism.

3. Excretion is the process of removing waste substances from the body. This process occurs both in the last stages of digestion and during metabolism. In the latter case, the excretion involves blood and special organs for excreting the breakdown products of nitrogenous substances - the kidneys.

Let us, however, take a closer look at metabolism itself.

Metabolism includes two processes, which are its two inseparable sides: catabolism and anabolism.

Catabolism is the process of breaking down substances, resulting in the extraction of energy and the production of smaller molecules. The end products of catabolism are carbon dioxide, water, and ammonia.

Catabolism in the human body and most living beings is characterized by the following features.

· In the process of catabolism, oxidation reactions predominate.

· Catabolism occurs with oxygen consumption.

· During catabolism, energy is released, approximately half of which is accumulated in the form of adenosine triphosphate (ATP) molecules. A significant portion of the energy is released in the form of heat.

Anabolism is a synthesis reaction. These processes are characterized by the following features.

· Anabolism is mainly a recovery reaction.

· During the process of anabolism, hydrogen is consumed.

· ATP serves as the energy source for anabolic reactions.

2. Structure and biological role of ATP

Adenosine triphosphate, or ATP for short, is the body's universal energy substance. ATP is a nucleotide, the molecule of which includes a nitrogenous base - adenine, a carbohydrate - ribose and three phosphoric acid residues.

A feature of the ATP molecule is that the second and third phosphoric acid residues are attached by an energy-rich bond, otherwise called a high-energy bond. Often compounds that have a macroergic connection (and we will encounter them in the process of studying the subject) are designated by the term “macroergies” or macroergic substances.

The structure of ATP can be reflected in the diagram

Adenine-ribose - F.K. - F.K. - F.K.

adenosine

When ATP is used as an energy source, it is usually eliminated by hydrolysis of the last phosphoric acid residue.

ATP + H2O > ADP + H3PO4 + energy

Under physiological conditions, that is, under the conditions that exist in a living cell, the splitting of a mole of ATP is accompanied by the release of 10 - 12 kcal of energy (43 -50 kJ).

The main consumers of ATP energy in the body are

· synthesis reactions;

· muscle activity;

· transport of molecules and ions across membranes.

Thus, the biological role of ATP is that this substance in the body is a kind of equivalent of the EURO or dollar in the economy. The main supplier of ATP in the cell is tissue respiration - the final stage of catabolism, which occurs in the mitochondria of most cells of the body.

3. Tissue respiration

Tissue respiration is the main method of producing ATP used by the vast majority of cells in the body.

In the process of tissue respiration, two hydrogen atoms are removed from the oxidized substance and transferred through the respiratory chain, consisting of enzymes and coenzymes, to molecular oxygen, delivered by blood from the air to all tissues of the body. As a result of the addition of oxygen and hydrogen atoms, water is formed. Due to the energy released during the movement of electrons along the respiratory chain, ATP is synthesized from ADP and phosphoric acid in mitochondria. Typically, the synthesis of three ATP molecules is accompanied by the formation of one water molecule.

As a substrate for oxidation in tissue respiration, various intermediate products of the breakdown of carbohydrates, fats and proteins are used. However, the intermediate products of the citric acid cycle, otherwise called the tricarboxylic acid cycle or the Krebs cycle, are most often subject to oxidation (isocitric, alpha-ketoglutaric, succinic, malic acids are substrates of the tricarboxylic acid cycle). The citric acid cycle is the final stage of catabolism, during which the oxidation of the acetic acid residue included in acetyl coenzyme A occurs to carbon dioxide and water. In turn, acetyl coenzyme A is a universal substance of the body into which, during its breakdown, the main organic substances - proteins, fats and carbohydrates - are converted. Tissue respiration is a complex enzymatic process. Tissue respiration enzymes are divided into three groups: nicotinamide dehydrogenases, flavin dehydrogenases and cytochromes. These enzymes make up the respiratory chain.

Nicotinamide dehydrogenases take away two hydrogen atoms from the oxidized substrate and attach it to the coenzyme molecule NAD (nicotinamide adenine dinucleotide). In this case, NAD transforms into its reduced form NAD.H2.

Flavin dehydrogenases remove two hydrogen atoms from NAD.H2 and temporarily attach them to FMN (flavin mononucleotide). This is a coenzyme that contains vitamin B2. Then two hydrogen atoms are transferred to flavin, which in turn transfers these atoms to the cytochromes.

Cytochromes are enzymes containing ferric iron ions, which, by adding hydrogen, become divalent. There are several cytochromes and they are designated by the Latin letters a, a-3 b, c. Cytochromes transfer hydrogen to molecular oxygen and water is formed.

When moving along the respiratory chain, energy is released, which is accumulated in the form of ATP molecules. This process is called oxidative or respiratory phosphorylation. At least 40 kg of ATP is produced in the body per day. These processes occur especially intensely in the muscles during physical work.

4. Anaerobic, microsomal and free radical oxidation

In some cases, the removal of a hydrogen atom from oxidizable substances occurs in the cytoplasm. These processes occur without the participation of oxygen. Therefore, the hydrogen acceptors here are different. Most often, hydrogen is added to pyruvic acid, which occurs during the breakdown of carbohydrates and amino acids. Pyruvic acid can add hydrogen and thus become lactate or lactic acid. This process, which occurs particularly in muscles when there is a lack of oxygen, is called anaerobic oxidation or glycolysis. Due to the energy released in the cytoplasm, ATP is also formed. The process of ATP formation in the cytoplasm is called anaerobic or substrate phosphorylation. This process is much less effective than tissue respiration.

In some cases, during oxidation, oxygen atoms are included in the molecules of the substances being oxidized. This oxidation occurs on the membranes of the endoplasmic reticulum and is called microsomal oxidation. Due to the inclusion of oxygen in the oxidized substrate, a hydroxyl group (-OH) is formed. Therefore, this process is often called hydroxylation. Ascorbic acid or vitamin C takes an active part in this process.

The biological role of this process is not related to ATP synthesis. It is as follows.

1. Oxygen atoms are included in the substance being synthesized.

2. Various toxic substances are neutralized, since the inclusion of an oxygen atom in the poison molecule reduces the toxicity of this poison, makes it water-soluble, and makes it easier for the kidneys to eliminate it.

In rare cases, oxygen entering the body from the air is converted into active forms (O2, HO2, HO+, H2 O2, etc.), called free radicals or oxidants.

Free oxygen radicals cause oxidation reactions affecting proteins, fats, and nucleic acids. This oxidation is called free radical oxidation.

This process has a particular effect on fatty acids. Lipid peroxidation (LPO) helps renew the lipid layer of biological membranes.

Free radical oxidation can also be harmful if it occurs too intensely. Therefore, the body has a special antioxidant system, the most important part of which is vitamin E (tocopherol).

SECTION 2. METABOLISM OF SEPARATE GROUPS OF SUBSTANCES

Topic 3. Structure and metabolism of carbohydrates

3. Pathways of carbohydrate catabolism. Hexose diphosphate pathway for the breakdown of glucose

1. General characteristics and classification of carbohydrates. Functions of carbohydrates in the body

Carbohydrates make up more than 80% of all organic compounds in the Earth's biosphere.

Glucose plays an exceptional role in the energy metabolism of the biosphere. It is this carbohydrate that is formed during photosynthesis. And it is precisely glucose that triggers energy metabolism in our body.

Carbohydrates are divided into three main classes: monosaccharides, oligosaccharides and polysaccharides.

Monosaccharides or simple sugars do not undergo hydrolysis and it is impossible to obtain simpler carbohydrates from them. Monosaccharides include: ribose, deoxyribose, glucose, fructose, galactose and others.

Oligosaccharides consist of several monosaccharides joined by covalent bonds. During hydrolysis, they break down into their constituent monosaccharides. An example of oligosaccharides are disaccharides, consisting of two molecules of monosaccharides. The most common disaccharides are sucrose (table sugar or cane sugar), consisting of glucose and fructose residues, lactose (milk sugar), consisting of glucose and galactose residues.

Polysaccharides are long, unbranched chains. Including hundreds and thousands of monosaccharide residues. The most famous of them - starch, cellulose, glycogen - consist of glucose residues.

The functions of carbohydrates in the body are very diverse.

1. Energy.

2. Structural function (part of cellular structures).

3. Protective (synthesis of immune bodies in response to antigens).

4. Anticoagulant (heparin).

5. Homeostatic (maintaining water-salt metabolism)

6. Mechanical (part of connective and supporting tissues).

2. Structure and biological role of glucose and glycogen. Glycogen synthesis and breakdown

The empirical formula of glucose is C6H12O6. It can have different spatial forms. In the human body, glucose is usually found in a cyclic form:

Free glucose in the human body is mainly found in the blood, where its content is fairly constant and ranges from 3.9 to 6.1 mmol/l.

Glucose is the main source of energy in the body.

Another carbohydrate typical for humans is glycogen. Glycogen consists of highly branched, large molecules containing tens of thousands of glucose residues. The empirical formula of glycogen is: (C6 H12 O5)n where n is the number of glucose residues.

The main glycogen reserves are concentrated in the liver and muscles.

Glycogen is a storage form of glucose.

Normally, 400 - 500 g of carbohydrates are supplied with food. These are mainly starch, fiber, sucrose, lactose, glycogen. Digestion of carbohydrates occurs in different parts of the digestive tract, starting with the oral cavity. It is carried out by amylase enzymes. The only carbohydrate that is not broken down in our body is fiber. All the rest are broken down into glucose, fructose, galactose, etc. and are involved in catabolic processes. A significant part of glucose is converted into glycogen in the liver. Between meals, some of the glycogen in the liver is converted into glucose, which enters the blood.

Glucose used for glycogen synthesis is pre-activated. Then, after a series of transformations, it forms glycogen. This process involves the nucleotide UTP (uridine triphosphate), which is similar in structure to ATP. During the reactions, an intermediate compound is formed - uridine diphosphate glucose (UDP-glucose). It is this compound that forms glycogen molecules by reacting with the so-called seed. The priming agent is the glycogen molecules present in the liver.

The reactions of glycogen formation are provided with energy by ATP molecules. Glycogen synthesis is accelerated by the hormone insulin.

The breakdown of glycogen in the liver occurs in the reverse order and ultimately produces glucose and phosphoric acid. This process is accelerated by the hormones glucagon and adrenaline. The breakdown of glycogen in muscles is stimulated by the hormone adrenaline, which is released into the blood during muscle work. At the same time, free glucose is not formed in the muscles and the path of glycogen breakdown is somewhat different.

3. Catabolism of carbohydrates. Hexose diphosphate pathway for the breakdown of glucose.

Glucose catabolism occurs in two ways.

· The main part of carbohydrates (up to 95%) undergoes breakdown along the hexose dinophosphate pathway. It is this path that is the main source of energy for the body.

· The rest of the glucose is broken down through the hexose monophosphate pathway.

The HDP pathway can occur in the absence of oxygen - anaerobically and in the presence of oxygen, that is, in aerobic conditions. This is a very complex chain of sequential reactions, the end result of which is the formation of carbon dioxide and water. This process can be divided into three stages, sequentially following each other.

The first stage, called glycolysis, occurs in the cytoplasm of cells. The end product of this stage is pyruvic acid.

1. The reaction is that glucose is converted to glucose-6phosphate.

Glucose + ATP > glucose-6-phosphate + ADP

2. Glucose 6-phosphate is converted to fructose 6-phosphate

3. Fructose-6-phosphate turns into frutose-1.6-phosphate

5. Then 1.3diphosphoglycerate is formed from phosphoglyceraldehyde

6. 1.3-diphosphoglycerate transforms into 3-phosphoglycerate,

7. which turns into 2-phosphoglycerate, and then

8 in phosphopyruvate, and that

9 in pyruvate (pyruvic acid).

The general equation for glycolysis looks like this:

Glucose + O2 + 8ADP + 8 H3PO4 > 2 Pyruvate + 2H2O + 8 ATP

The first stage of carbohydrate breakdown is practically reversible. From pyruvate, as well as from lactate (lactic acid) arising under anaerobic conditions, glucose can be synthesized, and from it glycogen.

The second and third stages of the GDP pathway occur in mitochondria. These steps require the presence of oxygen. During the second stage, carbon dioxide and two hydrogen atoms are split off from pyruvic acid. The separated hydrogen atoms are transferred through the respiratory chain to oxygen with the simultaneous synthesis of ATP. Acetic acid is formed from pyruvate. It attaches to a special substance, coenzyme A. This substance is a carrier of acid residues. The result of this process is the formation of the substance acetyl coenzyme A. This substance has high chemical activity.

Acetyl coenzyme A undergoes further oxidation in the tricarboxylic acid cycle. This is the third stage. The first reaction of the cycle is the interaction of acetyl coenzyme A with oxaloacetic acid to form citric acid. Therefore, these reactions are called the citric acid cycle. Forming a series of intermediate tricarboxylic acids, citric acid is again converted into oxalic-acetic acid and the cycle is repeated. The result of these reactions is the formation of separated hydrogen, which, passing through the respiratory chain (see the previous lecture), forms water with oxygen. As a result of all these reactions, 36 ATP molecules are formed. In total, the GDP pathway produces 38 ATP molecules per glucose molecule

Glucose + 6 O2 + 38 ADP + 38 H3 PO4 > 6CO2 + 6 H2O +38 ATP

The breakdown of glycogen adds another ATP molecule to the equation,

When there is a lack of oxygen, the aerobic pathway is interrupted by the formation of pyruvate, which is converted to lactate. As a result of such transformations, only two ATP molecules are formed.

4. Hexose monophosphate pathway of carbohydrate breakdown

As already emphasized above, the HMP pathway of carbohydrate breakdown is a side one. This pathway is found in the adrenal glands, red blood cells, adipose tissue, liver and occurs in the cytoplasm of cells.

The GMP pathway of glucose breakdown has an anabolic purpose and provides various synthesis reactions with ribose and hydrogen.

The GMF pathway can be divided into two stages, and the first stage necessarily occurs, but the second does not always occur.

The first stage begins with the transition of glucose into the active form glucose-6-phosphate, from which a carbon dioxide molecule and two pairs of hydrogen atoms are then split off, attached to the coenzyme NADP (nicotinamide adenine dinucleotide phosphate). The end product of the first stage is ribose 5-phosphate.

The NADP.H2 formed as a result of the first stage supplies hydrogen atoms to various synthesis processes, in particular for the synthesis of fatty acids and cholesterol. Ribose 5-phosphate is used for the synthesis of nucleotides, from which nucleic acids and coenzymes are then formed.

The second stage occurs when ribose-5-phosphate is not completely consumed for synthesis. Unused molecules of this substance interact with each other, during which they exchange groups of atoms and monosaccharides with different numbers of carbon atoms, such as trioses, pentoses, tetroses, and hexoses, appear as intermediate products. Ultimately, from six molecules of ribose-5-phosphate, 5 molecules of glucose-6-phosphate are formed.

Thus, the second stage makes this method of glucose breakdown cyclical, which is why it is called the pentose cycle.

The pentose cycle is a backup pathway of energy metabolism, which in some cases can play a leading role.

Topic 4. Structure and metabolism of fats and lipoids

3. Fat catabolism

4. Fat synthesis

1. Chemical structure and biological role of fats and lipoids

Fats or lipids are a group of structurally diverse substances that have the same physical and chemical properties: they are insoluble in water, but highly soluble in organic solvents (benzene, toluene, gasoline, hexane, etc.)

Fats are divided into two groups - fats themselves or lipids and fat-like substances or lipoids.

The fat molecule consists of glycerol and three fatty acid residues connected by an ester bond. These are the so-called true fats or triglycerides.

Fatty acids included in fats are divided into saturated and unsaturated. The former do not have double bonds and are also called saturated, while the latter have double bonds and are called unsaturated. There are also polyunsaturated fatty acids that have two or more double bonds. Such fatty acids are not synthesized in the human body and must be supplied with food, as they are necessary for the synthesis of some important lipoids. The more double bonds, the lower the melting point of fat. Unsaturated fatty acids make fats more liquid. There are many of them in vegetable oil.

Fats of different origins differ in the set of fatty acids that make up their composition.

Fats are insoluble in water. However, in the presence of special substances - emulsifiers - fats, when mixed with water, form a stable mixture - an emulsion. An example of an emulsion is milk, and an example of an emulsifier is soap - sodium salts of fatty acids. In the human body, bile acids and some proteins act as emulsifiers.

In the body of animals and humans, three classes of lipoids can be distinguished.

1. Phospholipids, consisting of fatty acids, alcohol and necessarily phosphoric acid.

2. Glycolipids, consisting of a fatty acid, alcohol and some simple carbohydrate, most often galactose.

3. Steroids containing a complex sterane ring.

The importance of fats and steroids in the body is very high.

· Fats are an important source of energy. From one gram of fat, the body extracts about 9 kcal of energy, which is 2 times more than from 1 g of carbohydrates.

· Fats protect the body from hypothermia and mechanical stress (for example, shock).

· Fatty acids and lipoids are part of many hormones.

· Lipoids are the most important components of cell membranes.

· Under the influence of UV radiation, vitamin D is formed from lipid cholesterol.

2. Digestion and absorption of fats

The daily diet usually contains 80-100 g of fat. Digestion of fat in the human body occurs in the small intestine. Fats are first converted into an emulsion with the help of bile acids. During the emulsification process, large fat droplets turn into small ones, which significantly increases their total surface area. Pancreatic juice enzymes - lipases, being proteins, cannot penetrate into fat droplets and only break down fat molecules located on the surface. Therefore, increasing the total surface area of ​​fat droplets due to emulsification significantly increases the efficiency of this enzyme. Under the action of lipase, fat is broken down by hydrolysis into glycerol and fatty acids.

Since there are a variety of fats in food, as a result of their digestion, a large number of varieties of fatty acids are formed.

Fat breakdown products are absorbed by the mucous membrane of the small intestine. Glycerin is soluble in water, so it is easily absorbed. Fatty acids that are insoluble in water are absorbed in the form of complexes with bile acids (complexes consisting of fatty and bile acids are called choleic acids). In the cells of the small intestine, choleic acids break down into fatty and bile acids. Bile acids from the wall of the small intestine enter the liver and are then released again into the cavity of the small intestine.

The released fatty acids in the cells of the wall of the small intestine recombine with glycerol, resulting in the formation of a fat molecule again. But only fatty acids that are part of human fat enter into this process. Thus, human fat is synthesized. This conversion of dietary fatty acids into your own fats is called fat resynthesis.

Resynthesized fats through the lymphatic vessels, bypassing the liver, enter the systemic circulation and are stored in fat depots. The main fat depots of the body are located in the subcutaneous fatty tissue, the greater and lesser omentum, and the perinephric capsule.

3. Fat catabolism

The use of fat as an energy source begins with its release from fat depots into the bloodstream. This process is called fat mobilization. Fat mobilization is accelerated by the action of the sympathetic nervous system and the hormone adrenaline.

In the liver, fat is hydrolyzed to glycerol and fatty acids.

Glycerol easily transforms into phosphoglyceraldehyde. This substance is also an intermediate product of carbohydrates and therefore is easily involved in carbohydrate metabolism.

Fatty acids combine with coenzyme A to form acyl-coenzyme A (acyl-CoA). these processes occur in the cytoplasm. Next, acyl-CoA transfers the fatty acid to cornetin. Cornetin carries the fatty acid inside the mitochondria and again gives it to coenzyme A, but this time to the mitochondria. In mitochondria, fatty acid oxidation occurs in two stages.

The first stage is β-oxidation. The carbon atom of the fatty acid located in the “beta” position undergoes oxidation. From the fatty acid bound to CoA, two hydrogen atoms are split off twice, which are then transferred through the respiratory chain to molecular oxygen. As a result, water is formed and five molecules of ATP are formed. This process is repeated many times until the fatty acid is completely converted to acetyl-CoA.

The second stage of oxidation is the tricarboxylic acid cycle, in which further oxidation of the acetic acid residue included in acetyl coenzyme A occurs to carbon dioxide and water. When one molecule of acetyl coenzyme A is oxidized, up to 12 molecules of ATP are released. Thus, the oxidation of fatty acids to carbon dioxide and water provides a large amount of energy. For example, from one molecule of palmitic acid (C15 H31COOH) 130 molecules of ATP are formed. However, due to the structural features of fatty acids (too many carbon atoms compared to oxygen), their oxidation is significantly more difficult compared to carbohydrates. Therefore, fat provides the body with energy during work of average power, but for a long time. Hence the conclusion that in order to burn fat you need to carry out work of medium power, but for a long time.

Beta oxidation scheme

With prolonged physical activity and excessive formation of acetyl coenzyme A, a condensation reaction of acetic acid occurs with the formation of ketone bodies. In muscles, kidneys and myocardium, these bodies again turn into acetyl coenzyme A. Thus, ketone bodies play an important role during long-term sports training. However, when overtrained, they can form acetone in the blood, which is released in sweat, urine and exhaled air.

Activation of the synthesis of ketone bodies during fasting. Dotted lines - the speed of metabolic pathways is reduced; solid lines - the speed of metabolic pathways is increased. During fasting, as a result of the action of glucagon, lipolysis in adipose tissue and 3-oxidation in the liver are activated. The amount of oxaloacetate in mitochondria decreases, since it, having been reduced to malate, enters the cytosol, where it is again converted into oxaloacetate and used in gluconeogenesis. As a result, the rate of TCA cycle reactions decreases and, accordingly, the oxidation of acetyl-CoA slows down. The concentration of acetyl-CoA in mitochondria increases, and the synthesis of ketone bodies is activated. The synthesis of ketone bodies also increases in diabetes mellitus

4. Fat synthesis

Fats are synthesized from glycerol and fatty acids

Glycerol in the body occurs during the breakdown of fat (food and own), and is also easily formed from carbohydrates.

Fatty acids are synthesized from acetyl coenzyme A. Acetyl coenzyme A is a universal metabolite. Its synthesis requires hydrogen and ATP energy. Hydrogen is obtained from NADP.H2. The body synthesizes only saturated and monosaturated (having one double bond) fatty acids. Fatty acids that have two or more double bonds in a molecule, called polyunsaturated, are not synthesized in the body and must be supplied with food. For fat synthesis, fatty acids can be used - products of hydrolysis of food and body fats.

All participants in fat synthesis must be in active form: glycerol in the form of glycerophosphate, and fatty acids in the form of acetyl coenzyme A. Fat synthesis occurs in the cytoplasm of cells (mainly adipose tissue, liver, small intestine). The pathways for fat synthesis are presented in the diagram.

It should be noted that glycerol and fatty acids can be obtained from carbohydrates. Therefore, with excessive consumption of them against the background of a sedentary lifestyle, obesity develops.

Topic 5. Structure and metabolism of nucleic acids

1. Structure of mononucleotides

3. Digestion of nucleic acids. Catabolism

4. Nucleotide synthesis

5. Nucleic acid synthesis

1. Structure of mononucleotides

By their structure, nucleic acids are polynucleotides, consisting of mononucleotides or nucleotides.

A nucleotide is a complex organic compound consisting of three parts: a nitrogenous base, a carbohydrate and phosphoric acid residues.

Nitrogen bases are heterocyclic organic compounds belonging to two classes - purines and pyrimidines. Among the purines, nucleic acids include adenine and guanine

And among the pyrimidines, cytosine, thymine (DNA) and uracil (RNA).

The carbohydrate components of nucleotides can be ribose (RNA) and deoxyribose (DNA)

The nitrogenous base bound to a carbohydrate is called a nucleoside.

Phosphoric acid is attached by an ester bond to the fifth carbon atom of ribose or deoxyribose. The nucleotides that make up nucleic acids have one phosphoric acid residue and are called mononucleotides. However, di- and trinucleotides are found in the cell.

For example, a nucleotide consisting of adenine, ribose and one phosphoric acid residue is called adenosine monophosphate or AMP, and a nucleotide consisting of cytosine and one phosphoric acid residue is called cytosine monophosphate or CMP.

2. Structure of nucleic acids

From a chemical point of view, nucleic acids are irregular polymers consisting of rather complex monomers called nucleotides.

There are two classes of nucleic acids in cells - DNA and RNA. DNA is deoxyribonucleic acid and RNA is ribonucleic acid.

The structure of DNA is very complex and unique. Each nucleotide that makes up DNA is made up of a deoxyribose sugar unit, a phosphoric acid unit, and a nitrogenous base. There are four types of nitrogenous bases: adenine, guanine, cytosine, and thymine. Nucleotides are linked into long chains using phosphorus-diester bonds.

In 1953, researchers James Watson and Francis Crick proposed a model that explained the structure of the DNA molecule. According to their theory, DNA consists of two helical chains connected by hydrogen bonds. The nitrogenous bases of both chains are located inside the helix and form hydrogen bonds. These bonds connect DNA strands not randomly, but according to the principle of complementarity or correspondence. The essence of this principle is as follows: if thymine is in one chain, then in the opposite chain it corresponds to adenine, and cytosine always stands opposite guanine. This means that when DNA is doubled, another can be completed on each of its chains, and instead of one molecule you get two at once.

The principle of complementarity underlies all processes associated with the implementation of genetic information: DNA replication (DNA doubling), transcription (RNA synthesis on DNA templates), and translation (protein biosynthesis based on RNA templates).

The diagrams below demonstrate the structure of DNA and the principle of complementarity.

DNA structure

Principle of complementarity

In addition to DNA, there are three types of RNA in cells: messenger RNA (i-RNA), transport RNA (t-RNA) and ribosomal RNA (r-RNA). They all differ from DNA in a number of features. Firstly, instead of the nitrogenous base thymine, they contain uracil. Second, instead of the sugar deoxyribose, they contain ribose. Thirdly, they are usually single-stranded.

3. Digestion and absorption of nucleic acids. Catabolism

About 1 g of nucleic acids enters the body with food per day.

Digestion of nucleic acids occurs in the small intestine. First, nucleic acids received from food are converted into mononucleotides under the action of pancreatic juice enzymes - nucleases. Then, under the influence of enzymes of the small intestine, phosphoric acid is cleaved from mononucleotides, and nucleosides are formed. Some of the nucleosides are then broken down into nitrogenous bases and carbohydrates.

The products of nucleic acid digestion enter the blood, and then the liver and other organs.

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