In any cell of our body, millions of biological substances flow chemical reactions. They are catalyzed by a variety of enzymes, which often require energy. Where does the cell get it? This question can be answered if we consider the structure of the ATP molecule - one of the main sources of energy.

ATP is a universal energy source

ATP stands for adenosine triphosphate, or adenosine triphosphate. The substance is one of the two most important sources of energy in any cell. The structure of ATP and biological role closely connected. Most biochemical reactions can occur only with the participation of molecules of a substance, this is especially true. However, ATP is rarely directly involved in the reaction: for any process to occur, the energy contained precisely in adenosine triphosphate is needed.

The structure of the molecules of the substance is such that the bonds formed between phosphate groups carry a huge amount of energy. Therefore, such bonds are also called macroergic, or macroenergetic (macro=many, large amount). The term was first introduced by the scientist F. Lipman, and he also proposed using the symbol ̴ to designate them.

It is very important for the cell to maintain a constant level of adenosine triphosphate. This is especially true for muscle cells and nerve fibers, because they are the most energy-dependent and require a high content of adenosine triphosphate to perform their functions.

The structure of the ATP molecule

Adenosine triphosphate consists of three elements: ribose, adenine and residues

Ribose- a carbohydrate that belongs to the pentose group. This means that ribose contains 5 carbon atoms, which are enclosed in a cycle. Ribose connects to adenine through a β-N-glycosidic bond on the 1st carbon atom. Phosphoric acid residues on the 5th carbon atom are also added to the pentose.

Adenine is a nitrogenous base. Depending on which nitrogenous base is attached to ribose, GTP (guanosine triphosphate), TTP (thymidine triphosphate), CTP (cytidine triphosphate) and UTP (uridine triphosphate) are also distinguished. All these substances are similar in structure to adenosine triphosphate and perform approximately the same functions, but they are much less common in the cell.

Phosphoric acid residues. A maximum of three phosphoric acid residues can be attached to ribose. If there are two or only one, then the substance is called ADP (diphosphate) or AMP (monophosphate). It is between the phosphorus residues that macroenergetic bonds are concluded, after the rupture of which 40 to 60 kJ of energy is released. If two bonds are broken, 80, less often - 120 kJ of energy is released. When the bond between ribose and the phosphorus residue is broken, only 13.8 kJ is released, so there are only two high-energy bonds in the triphosphate molecule (P ̴ P ̴ P), and in the ADP molecule there is one (P ̴ P).

These are the structural features of ATP. Due to the fact that a macroenergetic bond is formed between phosphoric acid residues, the structure and functions of ATP are interconnected.

The structure of ATP and the biological role of the molecule. Additional functions of adenosine triphosphate

In addition to energy, ATP can perform many other functions in the cell. Along with other nucleotide triphosphates, triphosphate is involved in the construction of nucleic acids. In this case, ATP, GTP, TTP, CTP and UTP are suppliers of nitrogenous bases. This property is used in processes and transcription.

ATP is also necessary for the functioning of ion channels. For example, the Na-K channel pumps 3 sodium molecules out of the cell and pumps 2 potassium molecules into the cell. This ion current is needed to maintain a positive charge on the outer surface of the membrane, and only with the help of adenosine triphosphate can the channel function. The same applies to proton and calcium channels.

ATP is the precursor of the second messenger cAMP (cyclic adenosine monophosphate) - cAMP not only transmits the signal received by cell membrane receptors, but is also an allosteric effector. Allosteric effectors are substances that speed up or slow down enzymatic reactions. Thus, cyclic adenosine triphosphate inhibits the synthesis of an enzyme that catalyzes the breakdown of lactose in bacterial cells.

The adenosine triphosphate molecule itself may also be an allosteric effector. Moreover, in such processes, ADP acts as an antagonist to ATP: if triphosphate accelerates the reaction, then diphosphate inhibits it, and vice versa. These are the functions and structure of ATP.

How is ATP formed in a cell?

The functions and structure of ATP are such that the molecules of the substance are quickly used and destroyed. Therefore, triphosphate synthesis is an important process in the formation of energy in the cell.

There are three most important methods for the synthesis of adenosine triphosphate:

1. Substrate phosphorylation.

2. Oxidative phosphorylation.

3. Photophosphorylation.

Substrate phosphorylation is based on multiple reactions occurring in the cell cytoplasm. These reactions are called glycolysis - anaerobic stage. As a result of 1 cycle of glycolysis, from 1 molecule of glucose two molecules are synthesized, which are then used to produce energy, and two ATP are also synthesized.

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

Cell respiration

Oxidative phosphorylation is the formation of adenosine triphosphate by transferring electrons along the membrane electron transport chain. As a result of this transfer, a proton gradient is formed on one side of the membrane and, with the help of the protein integral set of ATP synthase, molecules are built. The process takes place on the mitochondrial membrane.

The sequence of stages of glycolysis and oxidative phosphorylation in mitochondria is general process called breathing. After full cycle From 1 glucose molecule in a cell, 36 ATP molecules are formed.

Photophosphorylation

The process of photophosphorylation is the same as oxidative phosphorylation with only one difference: photophosphorylation reactions occur in the chloroplasts of the cell under the influence of light. ATP is produced during the light stage of photosynthesis, the main energy production process in green plants, algae and some bacteria.

During photosynthesis, electrons pass through the same electron transport chain, resulting in the formation of a proton gradient. The concentration of protons on one side of the membrane is the source of ATP synthesis. The assembly of molecules is carried out by the enzyme ATP synthase.

The average cell contains 0.04% adenosine triphosphate by weight. However, the most great importance observed in muscle cells: 0.2-0.5%.

There are about 1 billion ATP molecules in a cell.

Each molecule lives no more than 1 minute.

One molecule of adenosine triphosphate is renewed 2000-3000 times a day.

In total, the human body synthesizes 40 kg of adenosine triphosphate per day, and at any given time the ATP reserve is 250 g.

Conclusion

The structure of ATP and the biological role of its molecules are closely related. The substance plays a key role in life processes, because the high-energy bonds between phosphate residues contain a huge amount of energy. Adenosine triphosphate performs many functions in the cell, and therefore it is important to maintain a constant concentration of the substance. Decay and synthesis occur at high speed, since the energy of bonds is constantly used in biochemical reactions. This is an essential substance for any cell in the body. That's probably all that can be said about the structure of ATP.

In biology, ATP is the source of energy and the basis of life. ATP - adenosine triphosphate - is involved in metabolic processes and regulates biochemical reactions in organism.

What is this?

Chemistry will help you understand what ATP is. Chemical formula ATP molecules - C10H16N5O13P3. Remembering the full name is easy if you break it down into its component parts. Adenosine triphosphate or adenosine triphosphoric acid is a nucleotide consisting of three parts:

• adenine - purine nitrogenous base;
• ribose - a monosaccharide related to pentoses;
• three phosphoric acid residues.

Rice. 1. The structure of the ATP molecule.

More detailed transcript ATP is presented in the table.

ATP was first discovered by Harvard biochemists Subbarao, Lohman, and Fiske in 1929. In 1941, German biochemist Fritz Lipmann discovered that ATP is the source of energy for a living organism.

Energy generation

Phosphate groups are interconnected by high-energy bonds that are easily destroyed. During hydrolysis (interaction with water), the bonds of the phosphate group break down, releasing a large amount of energy, and ATP is converted into ADP (adenosine diphosphoric acid).

Conventionally, the chemical reaction looks like this:

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ATP + H2O → ADP + H3PO4 + energy

Rice. 2. ATP hydrolysis.

Part of the released energy (about 40 kJ/mol) is involved in anabolism (assimilation, plastic metabolism), while part is dissipated in the form of heat to maintain body temperature. With further hydrolysis of ADP, another phosphate group is split off, releasing energy and forming AMP (adenosine monophosphate). AMP does not undergo hydrolysis.

ATP synthesis

ATP is located in the cytoplasm, nucleus, chloroplasts, and mitochondria. ATP synthesis in an animal cell occurs in mitochondria, and in a plant cell - in mitochondria and chloroplasts.

ATP is formed from ADP and phosphate with the expenditure of energy. This process is called phosphorylation:

ADP + H3PO4 + energy → ATP + H2O

Rice. 3. Formation of ATP from ADP.

In plant cells, phosphorylation occurs during photosynthesis and is called photophosphorylation. In animals, the process occurs during respiration and is called oxidative phosphorylation.

In animal cells, ATP synthesis occurs in the process of catabolism (dissimilation, energy metabolism) during the breakdown of proteins, fats, and carbohydrates.

Functions

From the definition of ATP it is clear that this molecule is capable of providing energy. In addition to energy, adenosine triphosphoric acid performs other functions:

• is a material for the synthesis of nucleic acids;
• is part of enzymes and regulates chemical processes, accelerating or slowing down their progress;
• is a mediator - transmits a signal to synapses (places of contact between two cell membranes).

What have we learned?

From a 10th grade biology lesson we learned about the structure and functions of ATP - adenosine triphosphoric acid. ATP consists of adenine, ribose and three phosphoric acid residues. During hydrolysis, phosphate bonds are broken, which releases the energy necessary for the life of organisms.

Test on the topic

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ATP and other cell compounds(vitamins)

A particularly important role in the bioenergetics of the cell is played by the adenyl nucleotide, to which two phosphoric acid residues are attached. This substance is called adenosine triphosphoric acid(ATP).

Energy is stored in the chemical bonds between the phosphoric acid residues of the ATP molecule, which is released when organic phosphate is broken off: ATP = ADP + P + E, where P is the enzyme, E is the released energy. In this reaction, adenosine diphosphoric acid (ADP) is formed - the remainder of the ATP molecule and organic phosphate.

All cells use ATP energy for the processes of biosynthesis, movement, production of heat, nerve impulses, luminescence (for example, in luminescent bacteria), i.e. for all life processes.

ATP is a universal biological energy accumulator that synthesized in mitochondria (intracellular organelles).

Mitochondria thus plays the role of an “energy station” in the cell. The principle of ATP formation in the chloroplasts of plant cells is generally the same - the use of a proton gradient and the conversion of the energy of the electrochemical gradient into energy chemical bonds.

The light energy of the Sun and the energy contained in the food consumed is stored in ATP molecules. The supply of ATP in the cell is small. So, the ATP reserve in the muscle is enough for 20-30 contractions. With intense, but short-term work, muscles work exclusively due to the breakdown of the ATP contained in them. After finishing work, a person breathes heavily - during this period, carbohydrates and other substances are broken down (energy is accumulated) and the supply of ATP in the cells is restored by protons. Protons pass through this channel under the influence driving force electrochemical gradient. The energy of this process is used by an enzyme contained in the same protein complexes and capable of attaching a phosphate group to adenosine diphosphate (ADP), which leads to the synthesis of ATP.

Vitamins: Vita - life.

Vitamins - biologically active substances synthesized in the body or supplied with food, which in small quantities are necessary for normal metabolism and vital functions of the body.

In 1911 The Polish chemist K. Funk isolated a substance from rice bran that cured the paralysis of pigeons that ate only polished rice. Chemical analysis of this substance showed that it contains nitrogen.

Funk called the substance he discovered a vitamin (from the words “vita” - life and “amine” - containing nitrogen.

Biological role of vitamins lies in their regular effect on metabolism. Vitamins have catalytic properties, that is, the ability to stimulate chemical reactions occurring in the body, and also actively participate in the formation and function of enzymes. Vitamins affect absorption nutrients, contribute to normal cell growth and development of the entire organism. Being integral part enzymes, vitamins determine their normal function and activity. Thus, a lack of any vitamin in the body leads to disruption of metabolic processes.

Groups of vitamins:

DAILY REQUIREMENT FOR VITAMINS

C - ascorbic acid: 70 - 100 mg.

B - thiamine: 1.5 - 2.6 mg.

B - riboflavin: 1.8 - 3 mg.

A - retinol: 1.5 mg.

D - calciferol: for children and adults 100 IU,

up to 3 years 400 IU.

E - tocopherol: 15 - 20 mg.

ATP is the abbreviation for Adenosine Tri-Phosphoric Acid. You can also find the name Adenosine triphosphate. This is a nucleoid that plays a huge role in energy exchange in the body. Adenosine Tri-Phosphoric Acid is universal source energy, participating in all biochemical processes of the body. This molecule was discovered in 1929 by the scientist Karl Lohmann. And its significance was confirmed by Fritz Lipmann in 1941.

Structure and formula of ATP

If we talk about ATP in more detail, then this is a molecule that provides energy to all processes occurring in the body, including the energy for movement. When the ATP molecule is broken down, the muscle fiber contracts, resulting in the release of energy that allows contraction to occur. Adenosine triphosphate is synthesized from inosine in a living organism.

In order to give the body energy, adenosine triphosphate must go through several stages. First, one of the phosphates is separated using a special coenzyme. Each phosphate provides ten calories. The process produces energy and produces ADP (adenosine diphosphate).

If the body needs more energy to function, then another phosphate is separated. Then AMP (adenosine monophosphate) is formed. The main source for the production of Adenosine Triphosphate is glucose; in the cell it is broken down into pyruvate and cytosol. Adenosine triphosphate energizes long fibers that contain the protein myosin. It is what forms muscle cells.

At moments when the body is resting, the chain goes into reverse side, i.e. Adenosine Tri-Phosphoric acid is formed. Again, glucose is used for these purposes. The created Adenosine Triphosphate molecules will be reused as soon as necessary. When energy is not needed, it is stored in the body and released as soon as it is needed.

The ATP molecule consists of several, or rather, three components:

1. Ribose is a five-carbon sugar that forms the basis of DNA.
2. Adenine is the combined atoms of nitrogen and carbon.
3. Triphosphate.

At the very center of the adenosine triphosphate molecule is a ribose molecule, and its edge is the main one for adenosine. On the other side of ribose is a chain of three phosphates.

ATP systems

At the same time, you need to understand that ATP reserves will only be sufficient for the first two or three seconds motor activity, after which its level decreases. But at the same time, muscle work can only be carried out with the help of ATP. Thanks to special systems in the body, new ATP molecules are constantly synthesized. The inclusion of new molecules occurs depending on the duration of the load.

ATP molecules synthesize three main biochemical systems:

1. Phosphagen system (creatine phosphate).
2. Glycogen and lactic acid system.
3. Aerobic respiration.

Let's consider each of them separately.

Phosphagen system- if the muscles work for a short time, but extremely intensely (about 10 seconds), the phosphagen system will be used. In this case, ADP binds to creatine phosphate. Thanks to this system, constant circulation occurs small quantity Adenosine triphosphate in muscle cells. Since the muscle cells themselves also contain creatine phosphate, it is used to restore ATP levels after high-intensity short work. But within ten seconds the level of creatine phosphate begins to decrease - this energy is enough for a short race or intense strength training in bodybuilding.

Glycogen and lactic acid- supplies energy to the body more slowly than the previous one. It synthesizes ATP, which can be enough for one and a half minutes of intense work. In the process, glucose in muscle cells is formed into lactic acid through anaerobic metabolism.

Since in an anaerobic state oxygen is not used by the body, then this system provides energy in the same way as in the aerobic system, but time is saved. In anaerobic mode, muscles contract extremely powerfully and quickly. Such a system can allow you to run a four hundred meter sprint or a longer intense workout in the gym. But for a long time working in this way will not allow muscle soreness, which appears due to an excess of lactic acid.

Aerobic respiration- this system turns on if the workout lasts more than two minutes. Then the muscles begin to receive adenosine triphosphate from carbohydrates, fats and proteins. In this case, ATP is synthesized slowly, but the energy lasts for a long time - physical activity can last for several hours. This happens due to the fact that glucose breaks down without obstacles, it does not have any counteractions from outside - as lactic acid interferes with the anaerobic process.

The role of ATP in the body

From the previous description it is clear that the main role of adenosine triphosphate in the body is to provide energy for all the numerous biochemical processes and reactions in the body. Most energy-consuming processes in living beings occur thanks to ATP.

But besides this main function, adenosine triphosphate also performs others:

The role of ATP in the human body and life is well known not only to scientists, but also to many athletes and bodybuilders, since its understanding helps make training more effective and correctly calculate loads. For people who do strength training in the gym, sprinting and other sports, it is very important to understand what exercises need to be performed at one time or another. Thanks to this, you can form the desired body structure, work out the muscle structure, reduce excess weight and achieve other desired results.

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. B pure form 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. Are esters 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). Greatest amount of ATP found 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're talking about 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 energy sunlight. This pathway of ATP synthesis is characteristic only of cells capable of photosynthesis (green plants, cyanobacteria). The energy of sunlight quanta is used by photosynthetics in light phase photosynthesis to synthesize 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 you can also find this: “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 macronutrients included in active centers 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 through 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 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 mainly consist of carbon compounds, and the analogue of carbon is silicon, the content of which is earth's crust 300 times more than carbon, found 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