Where is atf involved? ATP molecule - what is it and what is its role in the body

The phosphorylation process is the reaction of transfer of a phosphoryl group from one compound to another with the participation of the kinase enzyme. ATP is synthesized by oxidative and substrate phosphorylation. Oxidative phosphorylation is the synthesis of ATP by adding inorganic phosphate to ADP using the energy released during the oxidation of bioorganic substances.

ADP + ~P → ATP

Substrate phosphorylation is the direct transfer of a phosphoryl group with a high-energy ADP bond for the synthesis of ATP.

Examples of substrate phosphorylation:

1. An intermediate product of carbohydrate metabolism is phosphoenolpyruvic acid, which transfers the ADP phosphoryl group with a high-energy bond:

Interaction of the intermediate product of the Krebs cycle - high-energy succinyl-Co-A - with ADP to form one molecule of ATP.

Let's look at the three main stages of energy release and ATP synthesis in the body.

The first stage (preparatory) includes digestion and absorption. At this stage, 0.1% of the energy of food compounds is released.

Second phase. After transportation, monomers (decomposition products of bioorganic compounds) enter cells, where they undergo oxidation. As a result of the oxidation of fuel molecules (amino acids, glucose, fats), the compound acetyl-Co-A is formed. During this stage, about 30% of the energy of food substances is released.

The third stage - the Krebs cycle - is a closed system of biochemical redox reactions. The cycle is named after the English biochemist Hans Krebs, who postulated and experimentally confirmed the basic reactions of aerobic oxidation. For his research, Krebs received the Nobel Prize (1953). The cycle has two more names:

The tricarboxylic acid cycle, since it includes reactions of transformation of tricarboxylic acids (acids containing three carboxyl groups);

Citric acid cycle, since the first reaction of the cycle is the formation of citric acid.

The Krebs cycle includes 10 reactions, four of which are redox. During the reactions, 70% of the energy is released.

The biological role of this cycle is extremely important, since it is the common end point of the oxidative breakdown of all major foods. This is the main mechanism of oxidation in the cell; it is figuratively called the metabolic “cauldron”. During the oxidation of fuel molecules (carbohydrates, amino acids, fatty acids), the body is provided with energy in the form of ATP. Fuel molecules enter the Krebs cycle after being converted into acetyl-Co-A.

In addition, the tricarboxylic acid cycle supplies intermediate products for biosynthetic processes. This cycle occurs in the mitochondrial matrix.

Consider the reactions of the Krebs cycle:

The cycle begins with the condensation of the four-carbon component oxaloacetate and the two-carbon component acetyl-Co-A. The reaction is catalyzed by citrate synthase and involves aldol condensation followed by hydrolysis. The intermediate is citril-Co-A, which is hydrolyzed into citrate and CoA:

IV. This is the first redox reaction.
The reaction is catalyzed by an α-oxoglutarate dehydrogenase complex consisting of three enzymes:

VII.

Succinyl contains a bond that is rich in energy. Cleavage of the thioester bond of succinyl-CoA is associated with phosphorylation of guanosine diphosphate (GDP):

Succinyl-CoA + ~ F +GDP Succinate + GTP +CoA

The phosphoryl group of GTP is easily transferred to ADP to form ATP:

GTP + ADP ATP + GDP

This is the only reaction in the cycle that is a substrate phosphorylation reaction.

VIII. This is the third redox reaction:

The Krebs cycle produces carbon dioxide, protons, and electrons. The four reactions of the cycle are redox, catalyzed by enzymes - dehydrogenases containing the coenzymes NAD and FAD. Coenzymes capture the resulting H + and ē and transfer them to the respiratory chain (biological oxidation chain). Elements of the respiratory chain are located on the inner membrane of mitochondria.

The respiratory chain is a system of redox reactions, during which there is a gradual transfer of H + and ē to O 2, which enters the body as a result of respiration. ATP is formed in the respiratory chain. The main carriers ē in the chain are iron- and copper-containing proteins (cytochromes), coenzyme Q (ubiquinone). There are 5 cytochromes in the chain (b 1, c 1, c, a, a 3).

The prosthetic group of cytochromes b 1, c 1, c is iron-containing heme. The mechanism of action of these cytochromes is that they contain an iron atom with variable valence, which can be in both an oxidized and reduced state as a result of the transfer of ē and H +.

Boost ATP Levels for Fast Recovery and Growth

ATP is a source of intracellular energy that controls almost all muscle functions and determines the level of strength and endurance. It also regulates the anabolic response to training, as well as the influence of most hormones at the cellular level. It is quite possible to assume that the more ATP contained in the muscles, the larger and more powerful they will be.

The fact is that intense training as a bodybuilder depletes the ATP stores in the muscles. And this state of emptiness can last for several days, preventing muscle growth. In particular, overtraining is the result of the body being in a state of ATP depletion for a long time. In order to restore ATP levels in your muscles, you must learn how to effectively use various ATP boosters.

ATP levels during exercise

Muscle contractions use the energy of ATP contained in muscle cells. However, with intensive cuts, the supply of this “fuel” is quickly exhausted. It is for this reason that you cannot continue to produce the same force forever. The harder you train, the more ATP you need. But the heavier the burden becomes, the more your cells lose the ability to recreate ATP. As a result, a heavy load will quickly knock you down, causing enormous frustration as it robs you of the ability to complete your last, most productive reps. That's when you start to feel muscle contractions, feel every fiber, but they all stop working due to lack of ATP.

In fact, ATP levels are one of the most limiting factors in training. It reduces the number of growth-promoting reps in each set. To make up for the lack of intensity at the end of a set, you perform more sets, resulting in a significant amount of ineffective low-intensity work.

Contrary to popular belief, ATP levels after performing a set are not at all zero. In fact, it is very far from zero. Medical research shows that muscle ATP levels decrease by 25% after 10 seconds of maximal muscle contraction (1). After 30 seconds of such effort, the ATP level is at around 50%. Therefore, you are still far from completely depleting your ATP reserves. But even a slight decrease in its level is enough to prevent your muscles from contracting as powerfully as you would like. Of course, ATP stores become increasingly depleted as you perform more than one set. Research has shown that 4 minutes of rest was not enough to fully restore ATP levels in type 2 fibers after 30 seconds of muscle contraction (2). Consequently, when you start the second set, the ATP reserve in the muscles is not optimal. As you perform more and more sets, ATP levels become less and less.

What happens to ATP after exercise?

After training is completed, ATP reserves may be significantly reduced. When you rest, you might expect your muscles to have a chance to recover. After all, the need for ATP at this time decreases, and production increases. However, remember that at the beginning of the recovery period, ATP levels are low, so it will take some time for them to return to normal. Which? Surprisingly, it will take 24 to 72 hours for ATP to be fully replenished.

If you are in a state of overtraining, your ATP levels will not return to normal, baseline levels. Although, unfortunately, ATP levels are somewhat reduced after exercise, they are still quite high. There are several reasons for this, including the following:

1) When you exercise, sodium accumulates in muscle cells. They must then get rid of sodium using a mechanism called the Na-K-ATPase pump. As the name suggests, this mechanism uses ATP as an energy source.

2) If your muscles hurt, it means a large amount of calcium has accumulated in them. They will try to return the calcium they contain to its natural stores, but this also requires a certain supply of ATP.

3) Another interesting aspect concerns the formation of glutamine. After training, the body's need for glutamine increases greatly. To cope with the increased need for glutamine, the body begins to produce more glutamine from other amino acids, such as branched chain amino acids. A state of “tug of war” arises. As the use of glutamine increases, the body's efforts to produce new glutamine also increase. The production of glutamine is very expensive from an energy point of view - meaning ATP. It occurs mainly in the muscles, but the level of ATP in the muscles after exercise is reduced, which interferes with the production of glutamine. After a certain period of time, its production no longer covers the increased need, which leads to a significant reduction in glutamine levels after training. On the other hand, to make this reduction minimal, the body tries to increase the rate of glutamine synthesis, using even more ATP. Consequently, muscle ATP consumption remains high for a long period of time after exercise and this causes muscle recovery to take too long.

ATP and diet

The process of training and muscle development is quite difficult even when you eat normally. But bodybuilders have to follow a low-carb diet from time to time. You can imagine how reducing food intake affects the energy levels in the cell. During a long-term restrictive diet, the energy balance in the muscles is disrupted, which makes it even more difficult to maintain normal ATP levels. This leads to decreased strength during training and prolonged recovery after training.

Functions of ATP

In addition to its primary function of providing energy for muscle contraction and controlling electrolyte levels in muscles, ATP performs many other functions in muscles. For example, it controls the rate of protein synthesis. Just as the construction of a building requires the availability of raw materials and a certain expenditure of energy, so does the construction of muscle tissue. The material is amino acids, and the energy source is ATP. Anabolism is one of the most energy-consuming processes that occurs within muscles.

It consumes so much ATP that when this substance is reduced by 30%, most of the anabolic reactions stop. Thus, fluctuations in ATP levels greatly affect the anabolic process.

This explains the fact that muscles do not grow during training. When a person exercises, their ATP levels are too low. And if you triggered the anabolic process at this point, it would further deplete your ATP supply, reducing your ability to contract muscles. The sooner ATP levels return to normal, the sooner the process of protein synthesis will begin. So while it's important to increase your ATP levels during a workout, it's even more important to do so post-workout for muscle growth. ATP is also necessary for anabolic hormones to work their magic. Both testosterone and insulin require ATP to function properly.

Paradoxically, the level of ATP also controls the rate of catabolism. Major proteolytic pathways require energy to break down muscle tissue. While you might assume that a post-workout reduction in ATP levels would save muscles from catabolism, unfortunately, this is not the case. When muscle ATP levels reach a lower threshold, other catabolic mechanisms that are independent of ATP are activated. The calcium contained in the cells begins to be removed from the cells, causing major disorders. A more advantageous option would be to enhance both the anabolic and catabolic processes than a strong catabolic process and a weak anabolic one. Therefore, the more ATP, the better.

How to Increase ATP Levels

As a bodybuilder, you have a huge arsenal of powerful tools to increase your ATP levels. In this article I will talk about the use of creatine, prohormones and ribose. I will not dwell on carbohydrates, since too much has already been written about them as a source of energy. Glutamine and branched chain amino acids also have a small effect on ATP production, but I won't go into detail about them at this time. It is important that you understand that all of these stimulants are characterized by different timing of operation, and therefore are only auxiliary.

The fastest-acting stimulant is D-ribose. The ATP molecule is created by the interaction of one adenine molecule, three phosphate groups and one ribose molecule. Thus, ribose is a necessary raw material for ATP synthesis. Ribose also controls the activity of the enzyme 5-phosphoribosyl-1-pyrophosphate, which is necessary for ATP resynthesis.

I recommend consuming at least 4 grams of ribose 45 minutes before your workout. Not only will your strength levels improve immediately, but ribose also prevents performance-impacting nerve fatigue as you add reps to your heaviest sets.

However, ribose acts not only as a stimulator of ATP production. Research has shown that it is effective in increasing ATP levels and increasing levels of uridine triphosphate, another, albeit lesser known, source of cellular energy. Uridine triphosphate is most important for slow-twitch fibers. Research shows that it has a strong anabolic effect on muscles. It also helps them get rid of sodium infestations by helping potassium move inside the muscle cells, which in turn spares ATP stores.

I consider creatine to be a moderate ATP stimulator, and the longest acting ATP stimulants are prohormones. I doubt that creatine can have a stimulating effect on ATP production in those who lead a sedentary lifestyle. However, as discussed above, intense physical activity reduces ATP levels for a long time. In this case, creatine can provide the necessary starting material for ATP resynthesis, thanks to its transformation into phosphocreatine within the muscles. An experiment conducted by European scientists showed that with the additional use of creatine by athletes at a high level of training for five days in the amount of 21 g per day, together with the consumption of 252 g of carbohydrates, the level of ATP in the muscles increased by as much as 9%, and when using the ATP precursor phosphocreatine - by 11% (3).

Regarding prohormones, animal studies have shown that the level of male hormones greatly influences the level of ATP in the muscles. When rats were castrated, the level of ATP in their muscles was reduced (4). When the rats were given testosterone, ATP levels were restored to normal levels. The results of this study proved the importance of taking testosterone stimulants, especially in the post-workout period, when testosterone levels are reduced even by simply consuming carbohydrates. You can use an intracrine testosterone stimulant such as androstenedione and endocrine stimulants such as nandrolone precursors. Thus, you can naturally regulate declining testosterone levels in the blood by replacing it with nandrolone, while also increasing testosterone levels in the muscles with androstenedione.
Ribose, creatine and prohormones are effective stimulators of ATP production. Taking them in combination will increase your strength levels during resistance training while improving muscle recovery and growth after training. Because their influence is distributed differently over time and they have different modes of action, they produce optimal results by working in synergy.

Energy of muscle activity

As already indicated, both phases of muscle activity - contraction and relaxation - occur with the obligatory use of energy, which is released during the hydrolysis of ATP.

However, ATP reserves in muscle cells are insignificant (at rest, the concentration of ATP in muscles is about 5 mmol/l), and they are sufficient for muscle work for 1-2 s. Therefore, to ensure longer muscle activity, ATP reserves must be replenished in the muscles. The formation of ATP in muscle cells directly during physical work is called ATP resynthesis and comes with energy consumption.

Thus, when muscles function, two processes simultaneously occur in them: ATP hydrolysis, which provides the necessary energy for contraction and relaxation, and ATP resynthesis, which replenishes the loss of this substance. If only the chemical energy of ATP is used to ensure muscle contraction and relaxation, then the chemical energy of a wide variety of compounds is suitable for ATP resynthesis: carbohydrates, fats, amino acids and creatine phosphate.

Structure and biological role of ATP

Adenosine triphosphate (ATP) is a nucleotide. The ATP (adenosine triphosphoric acid) molecule consists of the nitrogenous base adenine, the five-carbon sugar ribose and three phosphoric acid residues connected by a high-energy bond. When it is hydrolyzed, a large amount of energy is released. ATP is the main macroerg of the cell, an energy accumulator in the form of the energy of high-energy chemical bonds.

Under physiological conditions, i.e., under those conditions that exist in a living cell, the breakdown of a mole of ATP (506 g) is accompanied by the release of 12 kcal, or 50 kJ of energy.

Pathways for ATP formation

Aerobic oxidation (tissue respiration)

Synonyms: oxidative phosphorylation, respiratory phosphorylation, aerobic phosphorylation.

This pathway occurs in mitochondria.

The tricarboxylic acid cycle was first discovered by the English biochemist G. Krebs (Fig. 4).

The first reaction is catalyzed by the enzyme citrate synthase, in which the acetyl group of acetyl-CoA condenses with oxaloacetate, resulting in the formation of citric acid. Apparently, in this reaction, citril-CoA bound to the enzyme is formed as an intermediate product. Then the latter spontaneously and irreversibly hydrolyzes to form citrate and HS-CoA.

As a result of the second reaction, the resulting citric acid undergoes dehydration to form cis-aconitic acid, which, by adding a water molecule, becomes isocitric acid (isocitrate). These reversible hydration-dehydration reactions are catalyzed by the enzyme aconitate hydratase (aconitase). As a result, mutual movement of H and OH occurs in the citrate molecule.

Rice. 4. Tricarboxylic acid cycle (Krebs cycle)

The third reaction appears to limit the rate of the Krebs cycle. Isocitric acid is dehydrogenated in the presence of NAD-dependent isocitrate dehydrogenase. During the isocitrate dehydrogenase reaction, isocitric acid is simultaneously decarboxylated. NAD-dependent isocitrate dehydrogenase is an allosteric enzyme that requires ADP as a specific activator. In addition, the enzyme needs or ions to exhibit its activity.

During the fourth reaction, oxidative decarboxylation of α-ketoglutaric acid occurs to form the high-energy compound succinyl-CoA. The mechanism of this reaction is similar to the reaction of oxidative decarboxylation of pyruvate to acetyl-CoA; The α-ketoglutarate dehydrogenase complex is similar in structure to the pyruvate dehydrogenase complex. In both cases, 5 coenzymes take part in the reaction: TPP, lipoic acid amide, HS-CoA, FAD and NAD+.

The fifth reaction is catalyzed by the enzyme succinyl-CoA synthetase. During this reaction, succinyl-CoA, with the participation of GTP and inorganic phosphate, is converted into succinic acid (succinate). At the same time, the formation of a high-energy phosphate bond of GTP occurs due to the high-energy thioether bond of succinyl-CoA.

As a result of the sixth reaction, succinate is dehydrogenated to fumaric acid. The oxidation of succinate is catalyzed by succinate dehydrogenase.

in a molecule in which the coenzyme FAD is tightly (covalently) bound to the protein. In turn, succinate dehydrogenase is tightly bound to the inner mitochondrial membrane.

The seventh reaction is carried out under the influence of the enzyme fumarate hydratase (fumarase). The resulting fumaric acid is hydrated, the reaction product is malic acid (malate).

Finally, during the eighth reaction of the tricarboxylic acid cycle, under the influence of mitochondrial NAD-dependent malate dehydrogenase, L-malate is oxidized to oxaloacetate.

During one cycle turn, the oxidation of one acetyl-CoA molecule in the Krebs cycle and the oxidative phosphorylation system can produce 12 ATP molecules.

Anaerobic oxidation

Synonyms: substrate phosphorylation, anaerobic ATP synthesis. Proceeds in the cytoplasm, the separated hydrogen joins some other substance. Depending on the substrate, two pathways of anaerobic ATP resynthesis are distinguished: creatine phosphate (creatine kinase, alactic) and glycolytic (glycolysis, lactate). In the nervous case, the substrate is creatine phosphate, in the second - glucose.

These pathways occur without the participation of oxygen.

Continuation. See No. 11, 12, 13, 14, 15, 16/2005

Biology lessons in science classes

Advanced planning, grade 10

Lesson 19. Chemical structure and biological role of ATP

Equipment: tables on general biology, diagram of the structure of the ATP molecule, diagram of the relationship between plastic and energy metabolism.

I. Test of knowledge

Conducting a biological dictation “Organic compounds of living matter”

The teacher reads the abstracts under numbers, the students write down in their notebooks the numbers of those abstracts that match the content of their version.

Option 1 – proteins.
Option 2 – carbohydrates.
Option 3 – lipids.
Option 4 – nucleic acids.

1. In their pure form they consist only of C, H, O atoms.

2. In addition to C, H, O atoms, they contain N and usually S atoms.

3. In addition to C, H, O atoms, they contain N and P atoms.

4. They have a relatively small molecular weight.

5. The molecular weight can be from thousands to several tens and hundreds of thousands of daltons.

6. The largest organic compounds with a molecular weight of up to several tens and hundreds of millions of daltons.

7. They have different molecular weights - from very small to very high, depending on whether the substance is a monomer or a polymer.

8. Consist of monosaccharides.

9. Consist of amino acids.

10. Consist of nucleotides.

11. They are esters of higher fatty acids.

12. Basic structural unit: “nitrogen base–pentose–phosphoric acid residue.”

13. Basic structural unit: “amino acids”.

14. Basic structural unit: “monosaccharide”.

15. Basic structural unit: “glycerol–fatty acid.”

16. Polymer molecules are built from identical monomers.

17. Polymer molecules are built from similar, but not quite identical monomers.

18. They are not polymers.

19. They perform almost exclusively energy, construction and storage functions, and in some cases – protective.

20. In addition to energy and construction, they perform catalytic, signaling, transport, motor and protective functions;

21. They store and transmit the hereditary properties of the cell and organism.

Option 1 – 2; 5; 9; 13; 17; 20.
Option 2 – 1; 7; 8; 14; 16; 19.
Option 3 – 1; 4; 11; 15; 18; 19.
Option 4– 3; 6; 10; 12; 17; 21.

II. Learning new material

1. Structure of adenosine triphosphoric acid

In addition to proteins, nucleic acids, fats and carbohydrates, a large number of other organic compounds are synthesized in living matter. Among them, an important role is played in the bioenergetics of the cell. adenosine triphosphoric acid (ATP). ATP is found in all plant and animal cells. In cells, adenosine triphosphoric acid is most often present in the form of salts called adenosine triphosphates. The amount of ATP fluctuates and averages 0.04% (on average there are about 1 billion ATP molecules in a cell). The largest amount of ATP is contained in skeletal muscles (0.2–0.5%).

The ATP molecule consists of a nitrogenous base - adenine, a pentose - ribose and three phosphoric acid residues, i.e. ATP is a special adenyl nucleotide. Unlike other nucleotides, ATP contains not one, but three phosphoric acid residues. ATP refers to macroergic substances - substances containing a large amount of energy in their bonds.

Spatial model (A) and structural formula (B) of the ATP molecule

The phosphoric acid residue is cleaved from ATP under the action of ATPase enzymes. ATP has a strong tendency to detach its terminal phosphate group:

ATP 4– + H 2 O ––> ADP 3– + 30.5 kJ + Fn,

because this leads to the disappearance of the energetically unfavorable electrostatic repulsion between adjacent negative charges. The resulting phosphate is stabilized due to the formation of energetically favorable hydrogen bonds with water. The charge distribution in the ADP + Fn system becomes more stable than in ATP. This reaction releases 30.5 kJ (breaking a normal covalent bond releases 12 kJ).

In order to emphasize the high energy “cost” of the phosphorus-oxygen bond in ATP, it is usually denoted by the sign ~ and called a macroenergetic bond. When one molecule of phosphoric acid is removed, ATP is converted to ADP (adenosine diphosphoric acid), and if two molecules of phosphoric acid are removed, ATP is converted to AMP (adenosine monophosphoric acid). The cleavage of the third phosphate is accompanied by the release of only 13.8 kJ, so that there are only two actual high-energy bonds in the ATP molecule.

2. ATP formation in the cell

The supply of ATP in the cell is small. For example, ATP reserves in a muscle are enough for 20–30 contractions. But a muscle can work for hours and produce thousands of contractions. Therefore, along with the breakdown of ATP to ADP, reverse synthesis must continuously occur in the cell. There are several pathways for ATP synthesis in cells. Let's get to know them.

1. Anaerobic phosphorylation. Phosphorylation is the process of ATP synthesis from ADP and low molecular weight phosphate (Pn). In this case, we are talking about oxygen-free processes of oxidation of organic substances (for example, glycolysis is the process of oxygen-free oxidation of glucose to pyruvic acid). Approximately 40% of the energy released during these processes (about 200 kJ/mol glucose) is spent on ATP synthesis, and the rest is dissipated as heat:

C 6 H 12 O 6 + 2ADP + 2Pn ––> 2C 3 H 4 O 3 + 2ATP + 4H.

2. Oxidative phosphorylation is the process of ATP synthesis using the energy of oxidation of organic substances with oxygen. This process was discovered in the early 1930s. XX century V.A. Engelhardt. Oxygen processes of oxidation of organic substances occur in mitochondria. Approximately 55% of the energy released in this case (about 2600 kJ/mol glucose) is converted into the energy of chemical bonds of ATP, and 45% is dissipated as heat.

Oxidative phosphorylation is much more effective than anaerobic synthesis: if during the process of glycolysis, only 2 ATP molecules are synthesized during the breakdown of a glucose molecule, then 36 ATP molecules are formed during oxidative phosphorylation.

3. Photophosphorylation– the process of ATP synthesis using the energy of sunlight. This pathway of ATP synthesis is characteristic only of cells capable of photosynthesis (green plants, cyanobacteria). The energy of solar light quanta is used by photosynthetics during the light phase of photosynthesis for the synthesis of ATP.

3. Biological significance of ATP

ATP is at the center of metabolic processes in the cell, being a link between the reactions of biological synthesis and decay. The role of ATP in a cell can be compared to the role of a battery, since during the hydrolysis of ATP the energy necessary for various vital processes is released (“discharge”), and in the process of phosphorylation (“charging”) ATP again accumulates energy.

Due to the energy released during ATP hydrolysis, almost all vital processes in the cell and body occur: transmission of nerve impulses, biosynthesis of substances, muscle contractions, transport of substances, etc.

III. Consolidation of knowledge

Solving biological problems

Task 1. When we run fast, we breathe quickly, and increased sweating occurs. Explain these phenomena.

Problem 2. Why do freezing people start stamping and jumping in the cold?

Task 3. In the famous work of I. Ilf and E. Petrov “The Twelve Chairs”, among many useful tips one can find the following: “Breathe deeply, you are excited.” Try to justify this advice from the point of view of the energy processes occurring in the body.

IV. Homework

Start preparing for the test and test (dictate the test questions - see lesson 21).

Lesson 20. Generalization of knowledge in the section “Chemical organization of life”

Equipment: tables on general biology.

I. Generalization of knowledge of the section

Students work with questions (individually) followed by checking and discussion

1. Give examples of organic compounds, which include carbon, sulfur, phosphorus, nitrogen, iron, manganese.

2. How can you distinguish a living cell from a dead one based on its ionic composition?

3. What substances are found in the cell in undissolved form? What organs and tissues do they contain?

4. Give examples of macroelements included in the active sites of enzymes.

5. What hormones contain microelements?

6. What is the role of halogens in the human body?

7. How do proteins differ from artificial polymers?

8. How do peptides differ from proteins?

9. What is the name of the protein that makes up hemoglobin? How many subunits does it consist of?

10. What is ribonuclease? How many amino acids does it contain? When was it synthesized artificially?

11. Why is the rate of chemical reactions without enzymes low?

12. What substances are transported by proteins across the cell membrane?

13. How do antibodies differ from antigens? Do vaccines contain antibodies?

14. What substances do proteins break down into in the body? How much energy is released? Where and how is ammonia neutralized?

15. Give an example of peptide hormones: how are they involved in the regulation of cellular metabolism?

16. What is the structure of the sugar with which we drink tea? What three other synonyms for this substance do you know?

17. Why is the fat in milk not collected on the surface, but rather in the form of a suspension?

18. What is the mass of DNA in the nucleus of somatic and germ cells?

19. How much ATP is used by a person per day?

20. What proteins do people use to make clothes?

Primary structure of pancreatic ribonuclease (124 amino acids)

II. Homework.

Continue preparing for the test and test in the section “Chemical organization of life.”

Lesson 21. Test lesson on the section “Chemical organization of life”

I. Conducting an oral test on questions

1. Elementary composition of the cell.

2. Characteristics of organogenic elements.

3. Structure of the water molecule. Hydrogen bonding and its significance in the “chemistry” of life.

4. Properties and biological functions of water.

5. Hydrophilic and hydrophobic substances.

6. Cations and their biological significance.

7. Anions and their biological significance.

8. Polymers. Biological polymers. Differences between periodic and non-periodic polymers.

9. Properties of lipids, their biological functions.

10. Groups of carbohydrates, distinguished by structural features.

11. Biological functions of carbohydrates.

12. Elementary composition of proteins. Amino acids. Peptide formation.

13. Primary, secondary, tertiary and quaternary structures of proteins.

14. Biological function of proteins.

15. Differences between enzymes and non-biological catalysts.

16. Structure of enzymes. Coenzymes.

17. Mechanism of action of enzymes.

18. Nucleic acids. Nucleotides and their structure. Formation of polynucleotides.

19. Rules of E. Chargaff. The principle of complementarity.

20. Formation of a double-stranded DNA molecule and its spiralization.

21. Classes of cellular RNA and their functions.

22. Differences between DNA and RNA.

23. DNA replication. Transcription.

24. Structure and biological role of ATP.

25. Formation of ATP in the cell.

II. Homework

Continue preparing for the test in the section “Chemical organization of life.”

Lesson 22. Test lesson on the section “Chemical organization of life”

I. Conducting a written test

Option 1

1. There are three types of amino acids - A, B, C. How many variants of polypeptide chains consisting of five amino acids can be built. Please indicate these options. Will these polypeptides have the same properties? Why?

2. All living things consist mainly of carbon compounds, and the carbon analogue, silicon, the content of which in the earth’s crust is 300 times greater than carbon, is found only in very few organisms. Explain this fact in terms of the structure and properties of the atoms of these elements.

3. ATP molecules labeled with radioactive 32P at the last, third phosphoric acid residue were introduced into one cell, and ATP molecules labeled with 32P at the first residue closest to ribose were introduced into the other cell. After 5 minutes, the content of inorganic phosphate ion labeled with 32P was measured in both cells. Where will it be significantly higher?

4. Research has shown that 34% of the total number of nucleotides of this mRNA is guanine, 18% is uracil, 28% is cytosine and 20% is adenine. Determine the percentage composition of the nitrogenous bases of double-stranded DNA, of which the indicated mRNA is a copy.

Option 2

1. Fats constitute the “first reserve” in energy metabolism and are used when the reserve of carbohydrates is exhausted. However, in skeletal muscles, in the presence of glucose and fatty acids, the latter are used to a greater extent. Proteins are always used as a source of energy only as a last resort, when the body is starving. Explain these facts.

2. Ions of heavy metals (mercury, lead, etc.) and arsenic are easily bound by sulfide groups of proteins. Knowing the properties of sulfides of these metals, explain what will happen to the protein when combined with these metals. Why are heavy metals poisons for the body?

3. In the oxidation reaction of substance A into substance B, 60 kJ of energy is released. How many ATP molecules can be maximally synthesized in this reaction? How will the rest of the energy be used?

4. Studies have shown that 27% of the total number of nucleotides of this mRNA is guanine, 15% is uracil, 18% is cytosine and 40% is adenine. Determine the percentage composition of the nitrogenous bases of double-stranded DNA, of which the indicated mRNA is a copy.

To be continued

The cells of all organisms contain molecules of ATP - adenosine triphosphoric acid. ATP is a universal cell substance, the molecule of which has energy-rich bonds. The ATP molecule is one unique nucleotide, which, like other nucleotides, consists of three components: a nitrogenous base - adenine, a carbohydrate - ribose, but instead of one contains three residues of phosphoric acid molecules (Fig. 12). The bonds indicated in the figure are rich in energy and are called high-energy. Each ATP molecule contains two high-energy bonds.

When a high-energy bond is broken and one molecule of phosphoric acid is removed with the help of enzymes, 40 kJ/mol of energy is released, and ATP is converted into ADP - adenosine diphosphoric acid. When another molecule of phosphoric acid is removed, another 40 kJ/mol is released; AMP is formed - adenosine monophosphoric acid. These reactions are reversible, that is, AMP can be converted into ADP, ADP into ATP.

ATP molecules are not only broken down, but also synthesized, so their content in the cell is relatively constant. The importance of ATP in the life of a cell is enormous. These molecules play a leading role in the energy metabolism necessary to ensure the life of the cell and the organism as a whole.

An RNA molecule is usually a single chain, consisting of four types of nucleotides - A, U, G, C. Three main types of RNA are known: mRNA, rRNA, tRNA. The content of RNA molecules in a cell is not constant; they participate in protein biosynthesis. ATP is a universal energy substance of the cell, which contains energy-rich bonds. ATP plays a central role in cellular energy metabolism. RNA and ATP are found in both the nucleus and cytoplasm of the cell.

Any cell, like any living system, has the inherent ability to maintain its composition and all its properties at a relatively constant level. For example, the ATP content in cells is about 0.04%, and this value is firmly maintained, despite the fact that ATP is constantly consumed in the cell during life. Another example: the reaction of the cellular contents is slightly alkaline, and this reaction is stably maintained, despite the fact that acids and bases are constantly formed during the metabolic process. Not only the chemical composition of the cell, but also its other properties are firmly maintained at a certain level. The high stability of living systems cannot be explained by the properties of the materials from which they are built, since proteins, fats and carbohydrates have little stability. The stability of living systems is active; it is determined by complex processes of coordination and regulation.

Let us consider, for example, how the constancy of the ATP content in the cell is maintained. As we know, ATP is consumed by the cell when it carries out any activity. The synthesis of ATP occurs as a result of processes without oxygen and oxygen breakdown of glucose. It is obvious that the constancy of the ATP content is achieved due to the precise balancing of both processes - ATP consumption and its synthesis: as soon as the ATP content in the cell decreases, processes without oxygen and oxygen breakdown of glucose immediately turn on, during which ATP is synthesized and the ATP content in the cell increases. When ATP levels reach normal, ATP synthesis slows down.

Switching on and off processes that ensure the maintenance of the normal composition of the cell occurs automatically in it. This regulation is called self-regulation or autoregulation.

The basis for the regulation of cell activity are information processes, i.e. processes in which communication between individual links of the system is carried out using signals. A signal is a change that occurs in some link of the system. In response to the signal, a process is launched, as a result of which the resulting change is eliminated. When the normal state of the system is restored, this serves as a new signal to shut down the process.

How does the cell signaling system work, how does it ensure autoregulation processes in it?

Reception of signals inside the cell is carried out by its enzymes. Enzymes, like most proteins, have an unstable structure. Under the influence of a number of factors, including many chemical agents, the structure of the enzyme is disrupted and its catalytic activity is lost. This change is usually reversible, i.e., after eliminating the active factor, the structure of the enzyme returns to normal and its catalytic function is restored.

The mechanism of cell autoregulation is based on the fact that the substance, the content of which is regulated, is capable of specific interaction with the enzyme that generates it. As a result of this interaction, the structure of the enzyme is deformed and its catalytic activity is lost.

The cell autoregulation mechanism works as follows. We already know that chemicals produced in a cell typically arise from several sequential enzymatic reactions. Remember the oxygen-free and oxygen-free processes of glucose breakdown. Each of these processes represents a long series - at least a dozen sequential reactions. It is quite obvious that to regulate such polynomial processes, it is sufficient to turn off any one link. It is enough to turn off at least one reaction and the entire line will stop. It is in this way that the ATP content in the cell is regulated. While the cell is at rest, its ATP content is about 0.04%. At such a high concentration of ATP, it reacts with one of the enzymes without the oxygen process of breaking down glucose. As a result of this reaction, all molecules of this enzyme are devoid of activity and the conveyor lines without oxygen and oxygen processes are inactive. If, due to any activity of the cell, the concentration of ATP in it decreases, then the structure and function of the enzyme are restored and without oxygen and oxygen processes are started. As a result, ATP is produced and its concentration increases. When it reaches the standard (0.04%), the conveyor without oxygen and oxygen processes automatically turns off.

2241-2250

2241. Geographical isolation leads to speciation, since in populations of the original species there is
A) divergence
B) convergence
B) aromorphosis
D) degeneration

2242. Non-renewable natural resources of the biosphere include
A) lime deposits
B) tropical forests
B) sand and clay
D) coal

2243. What is the probability of a recessive trait manifesting itself in the phenotype in the first generation offspring if both parents have the Aa genotype?
A) 0%
B) 25%
B) 50%
D) 75%

Abstract

2244. Energy-rich bonds between phosphoric acid residues are present in the molecule
A) squirrel
B) ATP
B) mRNA
D) DNA

2245. On what basis is the animal depicted in the figure classified as an insect?
A) three pairs of walking legs
B) two simple eyes
B) one pair of transparent wings
D) dismemberment of the body into head and abdomen

Abstract

2246. A zygote, unlike a gamete, is formed as a result
A) fertilization
B) parthenogenesis
B) spermatogenesis
D) I division of meiosis

2247. Infertile hybrids in plants are formed as a result
A) intraspecific crossing
B) polyploidization
B) distant hybridization
D) analyzing crossing

How much ATP is contained in the body?

2249. In Rh-negative people, compared to Rh-positive people, red blood cells differ in composition
A) lipids
B) carbohydrates
B) minerals
D) proteins

2250. When cells of the temporal lobe of the cerebral cortex are destroyed, a person
A) gets a distorted idea of the shape of objects
B) does not distinguish between the strength and pitch of sound
B) loses coordination of movements
D) does not distinguish visual signals

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1. What words are missing from the sentence and replaced with letters (a-d)?

“The ATP molecule consists of a nitrogenous base (a), a five-carbon monosaccharide (b) and (c) an acid residue (d).”

The following words are replaced by letters: a – adenine, b – ribose, c – three, d – phosphoric.

2. Compare the structure of ATP and the structure of a nucleotide. Identify similarities and differences.

In fact, ATP is a derivative of the adenyl nucleotide of RNA (adenosine monophosphate, or AMP). The molecules of both substances include the nitrogenous base adenine and the five-carbon sugar ribose. The differences are due to the fact that the adenyl nucleotide of RNA (as in any other nucleotide) contains only one phosphoric acid residue, and there are no high-energy (high-energy) bonds. The ATP molecule contains three phosphoric acid residues, between which there are two high-energy bonds, so ATP can act as a battery and energy carrier.

3. What is the process of ATP hydrolysis?

ATF: energy currency

ATP synthesis? What is the biological role of ATP?

During the process of hydrolysis, one phosphoric acid residue is removed from the ATP molecule (dephosphorylation). In this case, the high-energy bond is broken, 40 kJ/mol of energy is released and ATP is converted into ADP (adenosine diphosphoric acid):

ATP + H2O → ADP + H3PO4 + 40 kJ

ADP can undergo further hydrolysis (which rarely occurs) with the elimination of another phosphate group and the release of a second “portion” of energy. In this case, ADP is converted into AMP (adenosine monophosphoric acid):

ADP + H2O → AMP + H3PO4 + 40 kJ

ATP synthesis occurs as a result of the addition of a phosphoric acid residue to the ADP molecule (phosphorylation). This process occurs mainly in mitochondria and chloroplasts, partly in the hyaloplasm of cells. To form 1 mole of ATP from ADP, at least 40 kJ of energy must be expended:

ADP + H3PO4 + 40 kJ → ATP + H2O

ATP is a universal storehouse (battery) and carrier of energy in the cells of living organisms. In almost all biochemical processes occurring in cells that require energy, ATP is used as an energy supplier. Thanks to the energy of ATP, new molecules of proteins, carbohydrates, lipids are synthesized, active transport of substances is carried out, the movement of flagella and cilia occurs, cell division occurs, muscles work, a constant body temperature is maintained in warm-blooded animals, etc.

4. What connections are called macroergic? What functions can substances containing high-energy bonds perform?

Macroergic bonds are those whose rupture releases a large amount of energy (for example, the rupture of each macroergic ATP bond is accompanied by the release of 40 kJ/mol of energy). Substances containing high-energy bonds can serve as batteries, carriers and suppliers of energy for various life processes.

5. The general formula of ATP is C10H16N5O13P3. When 1 mole of ATP is hydrolyzed to ADP, 40 kJ of energy is released. How much energy will be released during the hydrolysis of 1 kg of ATP?

● Calculate the molar mass of ATP:

M (C10H16N5O13P3) = 12 × 10 + 1 × 16 + 14 × 5 + 16 × 13 + 31 × 3 = 507 g/mol.

● When 507 g of ATP (1 mol) is hydrolyzed, 40 kJ of energy is released.

This means that upon hydrolysis of 1000 g of ATP, the following will be released: 1000 g × 40 kJ: 507 g ≈ 78.9 kJ.

Answer: When 1 kg of ATP is hydrolyzed to ADP, about 78.9 kJ of energy will be released.

6. ATP molecules labeled with radioactive phosphorus 32P at the last (third) phosphoric acid residue were introduced into one cell, and ATP molecules labeled with 32P at the first (closest to ribose) residue were introduced into the other cell. After 5 minutes, the content of inorganic phosphate ion labeled with 32P was measured in both cells. Where was it higher and why?

The last (third) phosphoric acid residue is easily cleaved off during the hydrolysis of ATP, and the first (closest to ribose) is not cleaved off even during the two-step hydrolysis of ATP to AMP. Therefore, the content of radioactive inorganic phosphate will be higher in the cell into which ATP, labeled at the last (third) phosphoric acid residue, was introduced.

Dashkov M.L.

Website: dashkov.by

An RNA molecule, unlike DNA, is usually a single chain of nucleotides, which is much shorter than DNA. However, the total mass of RNA in a cell is greater than DNA. RNA molecules are present in both the nucleus and the cytoplasm.

Three main types of RNA are known: informational, or template, - mRNA; ribosomal - rRNA, transport - tRNA, which differ in the shape, size and functions of the molecules. Their main function is participation in protein biosynthesis.

You see that an RNA molecule, like a DNA molecule, consists of four types of nucleotides, three of which contain the same nitrogenous bases as DNA nucleotides (A, G, C). However, instead of the nitrogenous base thymine, RNA contains another nitrogenous base - uracil (U). Thus, the nucleotides of an RNA molecule include nitrogenous bases: A, G, C, U. In addition, instead of the carbohydrate deoxyribose, RNA contains ribose.

The cells of all organisms contain molecules of ATP - adenosine triphosphoric acid. ATP is a universal cell substance, the molecule of which has energy-rich bonds. The ATP molecule is one unique nucleotide, which, like other nucleotides, consists of three components: a nitrogenous base - adenine, a carbohydrate - ribose, but instead of one it contains three residues of phosphoric acid molecules. Each ATP molecule contains two high-energy bonds.

ATP molecule - what is it and what is its role in the body

ATP molecules are not only broken down, but also synthesized, and therefore their content in the cell is relatively constant. The importance of ATP in the life of a cell is enormous. These molecules play a leading role in the energy metabolism necessary to ensure the life of the cell and the organism as a whole.