The basis of all living processes is atomic-molecular movement. Both the respiratory process and cellular development and division are impossible without energy. The source of energy supply is ATP; what it is and how it is formed will be discussed below.

Before studying the concept of ATP, it is necessary to decipher it. This term means nucleoside triphosphate, which is essential for energy and material metabolism in the body.

This is a unique energy source underlying biochemical processes. This compound is fundamental for enzymatic formation.

ATP was discovered at Harvard in 1929. The founders were scientists from Harvard Medical School. These included Karl Lohman, Cyrus Fiske and Yellapragada Subbarao. They identified a compound whose structure resembled the adenyl nucleotide of ribonucleic acids.

A distinctive feature of the compound was the content of three phosphoric acid residues instead of one. In 1941, scientist Fritz Lipmann proved that ATP has energy potential within the cell. Subsequently, a key enzyme was discovered, which was called ATP synthase. Its task is the formation of acidic molecules in mitochondria.

ATP is an energy accumulator in cell biology and is essential for the successful implementation of biochemical reactions.

The biology of adenosine triphosphoric acid suggests its formation as a result of energy metabolism. The process consists of creating 2 molecules in the second stage. The remaining 36 molecules appear in the third stage.

The accumulation of energy in the acid structure occurs in the connecting part between phosphorus residues. In the case of detachment of 1 phosphorus residue, an energy release of 40 kJ occurs.

As a result, the acid is converted into adenosine diphosphate (ADP). Subsequent phosphate abstraction promotes the appearance of adenosine monophosphate (AMP).

It should be noted that the plant cycle involves the reuse of AMP and ADP, which results in the reduction of these compounds to an acid state. This is ensured by the process.

Structure

Disclosure of the essence of a compound is possible after studying which compounds are part of the ATP molecule.

What compounds are included in the acid:

• 3 phosphoric acid residues. Acidic residues are combined with each other through energetic bonds of an unstable nature. Also found under the name phosphoric acid;
• adenine: Is a nitrogenous base;
• Ribose: Is a pentose carbohydrate.

The inclusion of these elements in ATP gives it a nucleotide structure. This allows the molecule to be classified as a nucleic acid.

Important! As a result of the cleavage of acidic molecules, energy is released. The ATP molecule contains 40 kJ of energy.

Education

The formation of the molecule occurs in mitochondria and chloroplasts. The fundamental point in the molecular synthesis of acid is the dissimilation process. Dissimilation is the process of transition of a complex compound to a relatively simple one due to destruction.

Within the framework of acid synthesis, it is customary to distinguish several stages:

1. Preparatory. The basis of splitting is the digestive process, ensured by enzymatic action. Food that enters the body undergoes decay. Fat decomposition occurs into fatty acids and glycerol. Proteins break down to amino acids, starch to the formation of glucose. The stage is accompanied by the release of thermal energy.
2. Anoxic, or glycolysis. It is based on the process of decay. Glucose breakdown occurs with the participation of enzymes, while 60% of the released energy is converted into heat, the rest remains in the molecule.
3. Oxygen, or hydrolysis; It takes place inside mitochondria. Occurs with the help of oxygen and enzymes. Oxygen exhaled by the body is involved. Ends complete. Involves the release of energy to form a molecule.

The following pathways of molecular formation exist:

1. Phosphorylation of a substrate nature. Based on the energy of substances resulting from oxidation. The predominant part of the molecule is formed in mitochondria on membranes. It is carried out without the participation of membrane enzymes. It occurs in the cytoplasmic part through glycolysis. The option of formation due to the transport of the phosphate group from other high-energy compounds is allowed.
2. Oxidative phosphorylation. Occurs due to an oxidative reaction.
3. Photophosphorylation in plants during photosynthesis.

Meaning

The fundamental significance of a molecule for the body is revealed through the function that ATP performs.

ATP functionality includes the following categories:

1. Energy. Provides the body with energy and is the energy basis for physiological biochemical processes and reactions. Occurs due to 2 high-energy bonds. Involves muscle contraction, the formation of transmembrane potential, and ensuring molecular transport across membranes.
2. The basis of synthesis. It is considered the starting compound for the subsequent formation of nucleic acids.
3. Regulatory. It underlies the regulation of most biochemical processes. Provided by belonging to an allosteric effector of the enzymatic series. Affects the activity of regulatory centers by enhancing or suppressing them.
4. Intermediary. It is considered a secondary link in the transmission of hormonal signals into the cell. It is a precursor to the formation of cyclic ADP.
5. Mediator. It is a signaling substance in synapses and other cellular interactions. Purinergic signaling is provided.

Among the above points, the dominant place is given to the energy function of ATP.

It's important to understand, no matter what function ATP performs, its importance is universal.

Useful video

Let's sum it up

The basis of physiological and biochemical processes is the existence of the ATP molecule. The main task of the connections is energy supply. Without the connection, the life activity of both plants and animals is impossible.

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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, living matter synthesizes a large number of other organic compounds. 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 ways 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 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 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 most important substance in the cells of living organisms is adenosine triphosphate or adenosine triphosphate. If we enter the abbreviation of this name, we get ATP. This substance belongs to the group of nucleoside triphosphates and plays a leading role in metabolic processes in living cells, being an irreplaceable source of energy for them.

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The discoverers of ATP were biochemists from the Harvard School of Tropical Medicine - Yellapragada Subbarao, Karl Lohman and Cyrus Fiske. The discovery occurred in 1929 and became a major milestone in the biology of living systems. Later, in 1941, German biochemist Fritz Lipmann discovered that ATP in cells is the main carrier of energy.

ATP structure

This molecule has a systematic name, which is written as follows: 9-β-D-ribofuranosyladenine-5′-triphosphate, or 9-β-D-ribofuranosyl-6-amino-purine-5′-triphosphate. What compounds make up ATP? Chemically, it is adenosine triphosphate ester - derivative of adenine and ribose. This substance is formed by combining adenine, which is a purine nitrogenous base, with the 1′-carbon of ribose using a β-N-glycosidic bond. α-, β-, and γ-phosphoric acid molecules are then sequentially added to the 5′-carbon of ribose.

Thus, the ATP molecule contains compounds such as adenine, ribose and three phosphoric acid residues. ATP is a special compound containing bonds that release large amounts of energy. Such bonds and substances are called high-energy. During the hydrolysis of these bonds of the ATP molecule, an amount of energy is released from 40 to 60 kJ/mol, and this process is accompanied by the elimination of one or two phosphoric acid residues.

This is how these chemical reactions are written:

• 1). ATP + water → ADP + phosphoric acid + energy;
• 2). ADP + water →AMP + phosphoric acid + energy.

The energy released during these reactions is used in further biochemical processes that require certain energy inputs.

The role of ATP in a living organism. Its functions

What function does ATP perform? First of all, energy. As mentioned above, the main role of adenosine triphosphate is to provide energy for biochemical processes in a living organism. This role is due to the fact that, due to the presence of two high-energy bonds, ATP acts as a source of energy for many physiological and biochemical processes that require large energy inputs. Such processes are all reactions of the synthesis of complex substances in the body. This is, first of all, the active transfer of molecules across cell membranes, including participation in the creation of intermembrane electrical potential, and the implementation of muscle contraction.

In addition to the above, we list a few more: no less important functions of ATP, such as:

How is ATP formed in the body?

The synthesis of adenosine triphosphoric acid is ongoing, because the body always needs energy for normal functioning. At any given moment, there is very little of this substance - approximately 250 grams, which is an “emergency reserve” for a “rainy day.” During illness, intensive synthesis of this acid occurs, because a lot of energy is required for the functioning of the immune and excretory systems, as well as the body’s thermoregulation system, which is necessary to effectively combat the onset of the disease.

Which cells have the most ATP? These are cells of muscle and nervous tissue, since energy exchange processes occur most intensively in them. And this is obvious, because muscles participate in movement that requires contraction of muscle fibers, and neurons transmit electrical impulses, without which the functioning of all body systems is impossible. This is why it is so important for the cell to maintain a constant and high level of adenosine triphosphate.

How can adenosine triphosphate molecules be formed in the body? They are formed by the so-called phosphorylation of ADP (adenosine diphosphate). This chemical reaction as follows:

ADP + phosphoric acid + energy → ATP + water.

Phosphorylation of ADP occurs with the participation of catalysts such as enzymes and light, and is carried out in one of three ways:

Both oxidative and substrate phosphorylation uses the energy of substances that are oxidized during such synthesis.

Conclusion

Adenosine triphosphoric acid- This is the most frequently renewed substance in the body. How long does an adenosine triphosphate molecule live on average? In the human body, for example, its lifespan is less than one minute, so one molecule of such a substance is born and decays up to 3000 times per day. Amazingly, during the day human body synthesizes about 40 kg of this substance! The need for this “internal energy” is so great for us!

The entire cycle of synthesis and further use of ATP as energy fuel for metabolic processes in the body of a living being represents the very essence of energy metabolism in this organism. Thus, adenosine triphosphate is a kind of “battery” that ensures the normal functioning of all cells of a living organism.

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 the body.

What is this?

Chemistry will help you understand what ATP is. The chemical formula of the ATP molecule is 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.

A more detailed explanation of 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.

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Millions of biochemical reactions take place in any cell of our body. 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 its biological role are closely related. 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 constitutes a common process called respiration. After a complete cycle, 36 ATP molecules are formed from 1 glucose molecule in the cell.

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.