ATP structure and biological role. Functions of ATP. ATP and its role in metabolism
ATP is the abbreviation for Adenosine Tri-Phosphoric Acid. You can also find the name Adenosine triphosphate. This is the nucleoid that plays huge role in the exchange of energy in the body. Adenosine Tri-Phosphoric acid is a universal source of energy involved 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:
- Ribose is a five-carbon sugar that forms the basis of DNA.
- Adenine is the combined atoms of nitrogen and carbon.
- Triphosphate.
At the very center of the Adenosine Triphosphate molecule there 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 be sufficient only for the first two or three seconds of physical 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 New ATP molecules are constantly synthesized in the body. The inclusion of new molecules occurs depending on the duration of the load.
ATP molecules synthesize three main biochemical systems:
- Phosphagen system (creatine phosphate).
- Glycogen and lactic acid system.
- 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, a small amount of Adenosine Triphosphate is constantly circulated 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 power load 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 may last 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 in addition to 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 are involved 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 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. 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). Largest quantity
ATP is 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,
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.
3. 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. 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 solar light quanta is used by photosynthetics during the light phase of photosynthesis for the synthesis of ATP. 3. Biological significance of ATP between reactions of biological synthesis and decomposition. 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
Equipment: 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”
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 one distinguish by ionic composition
living cell
from the dead?
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?
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 functions 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.”
Option 1
Lesson 22. Test lesson on the section “Chemical organization of life”
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. Research has shown that 27% total number The nucleotides of this mRNA are guanine, 15% are uracil, 18% are cytosine and 40% are adenine.
Determine the percentage composition of the nitrogenous bases of double-stranded DNA, of which the indicated mRNA is a copy.
To be continued
Ways to obtain energy in a cell
There are four main processes in the cell that ensure the release of energy from chemical bonds during the oxidation of substances and its storage: 1. Glycolysis (stage 2 biological oxidation ) – oxidation of a glucose molecule to two molecules of pyruvic acid, resulting in the formation of 2 molecules ATP And NADH
2. . Further, pyruvic acid is converted into acetyl-SCoA under aerobic conditions, and into lactic acid under anaerobic conditions.(stage 2 of biological oxidation) – oxidation of fatty acids to acetyl-SCoA, molecules are formed here And ATP FADN 2. ATP molecules do not appear “in their pure form”.
3. Tricarboxylic acid cycle(TCA cycle, stage 3 of biological oxidation) - oxidation of the acetyl group (as part of acetyl-SCoA) or other keto acids to carbon dioxide. Reactions full cycle accompanied by the formation of 1 molecule GTF(equivalent to one ATP), 3 molecules And and 1 molecule FADN 2.
4. Oxidative phosphorylation(stage 3 of biological oxidation) – NADH and FADH 2 obtained in the catabolism reactions of glucose, amino acids and fatty acids are oxidized. At the same time, enzymes of the respiratory chain on the inner membrane of mitochondria ensure the formation greater parts of the cell ) – oxidation of a glucose molecule to two molecules of pyruvic acid, resulting in the formation of 2 molecules.
Two ways to synthesize ATP
All nucleosides are constantly used in the cell three phosphates (ATP, GTP, CTP, UTP, TTP) as an energy donor. In this case, ATP is universal macroerg, involved in almost all aspects of metabolism and cell activity. And it is ATP that ensures the phosphorylation of the nucleotides GDP, CDP, UDP, TDP to nucleoside three phosphates.
Others have a nucleoside three There is a certain specialization in phosphates. Thus, UTP is involved in carbohydrate metabolism, in particular in the synthesis of glycogen. GTP is involved in ribosomes and participates in the formation of peptide bonds in proteins. CTP is used in the synthesis of phospholipids.
The main way to produce ATP in the cell is oxidative phosphorylation, which occurs in the structures of the inner mitochondrial membrane. In this case, the energy of the hydrogen atoms of the NADH and FADH 2 molecules formed in glycolysis, the TCA cycle, and the oxidation of fatty acids is converted into the energy of ATP bonds.
However, there is also another way to phosphorylate ADP to ATP - substrate phosphorylation. This method is associated with the transfer of high-energy phosphate or high-energy bond energy of any substance (substrate) to ADP. These substances include glycolytic metabolites ( 1,3-diphosphoglyceric acid, phosphoenolpyruvate), tricarboxylic acid cycle ( succinyl-SCoA) and reserve macroerg creatine phosphate. The energy of hydrolysis of their macroergic bond is higher than 7.3 kcal/mol in ATP, and the role of these substances is reduced to using this energy to phosphorylate the ADP molecule to ATP.
Classification of macroergs
High-energy compounds are classified according to type of connection, carrying additional energy:
1. Phosphoanhydride connection. All nucleotides have such a bond: nucleoside triphosphates (ATP, GTP, CTP, UTP, TTP) and nucleoside diphosphates (ADP, HDP, CDP, UDP, TDP).
2. Thioester connection. An example is the acyl derivatives of coenzyme A: acetyl-SCoA, succinyl-SCoA, and other compounds of any fatty acid and HS-CoA.
3. Guanidine phosphate connection - present in creatine phosphate, a reserve macroerg of muscle and nervous tissue.
4. Acylphosphate connection. These macroergs include the glycolytic metabolite 1,3-diphosphoglyceric acid (1,3-diphosphoglycerate). It ensures the synthesis of ATP in the reaction of substrate phosphorylation.
5. Enol phosphate connection. The representative is phosphoenolpyruvate, a metabolite of glycolysis. It also provides ATP synthesis in the substrate phosphorylation reaction in glycolysis.
This molecule plays an extremely important role in metabolism, the compound is known as a universal source of energy in all processes occurring in a living organism
Answer
The main source of energy for the cell is nutrients: carbohydrates, fats and proteins, which are oxidized with the help of oxygen. Almost all carbohydrates, before reaching the body cells, due to the work gastrointestinal tract and liver are converted into glucose. Along with carbohydrates, proteins are also broken down into amino acids and lipids into fatty acids. In the cell, nutrients are oxidized under the influence of oxygen and with the participation of enzymes that control energy release reactions and its utilization. Almost all oxidative reactions occur in mitochondria, and the released energy is stored in the form of a high-energy compound - ATP. Subsequently, it is ATP, and not nutrients, that is used to provide intracellular metabolic processes with energy.
The ATP molecule contains: (1) the nitrogenous base adenine; (2) pentose carbohydrate ribose, (3) three phosphoric acid residues. The last two phosphates are connected to each other and to the rest of the molecule by high-energy phosphate bonds, indicated on the ATP formula by the symbol ~. Subject to the physical and chemical conditions characteristic of the body, the energy of each such bond is 12,000 calories per 1 mole of ATP, which is many times higher than the energy of an ordinary chemical bond, which is why phosphate bonds are called high-energy.
Moreover, these connections are easily destroyed, providing intracellular processes with energy as soon as the need arises.
When energy is released, ATP donates a phosphate group and becomes adenosine diphosphate. The released energy is used for almost all cellular processes, for example in biosynthesis reactions and muscle contraction.
Replenishment of ATP reserves occurs by recombining ADP with a phosphoric acid residue at the expense of nutrient energy. This process is repeated again and again. ATP is constantly used up and stored, which is why it is called the energy currency of the cell. ATP turnover time is only a few minutes.
The role of mitochondria in the chemical reactions of ATP formation. When glucose enters the cell, it is converted into pyruvic acid under the action of cytoplasmic enzymes (this process is called glycolysis). The energy released in this process is spent on converting a small amount of ADP into ATP, representing less than 5% of the total energy reserves. ATP synthesis is 95% carried out in mitochondria. Pyruvic acid, fatty acids and amino acids, formed respectively from carbohydrates, fats and proteins, are eventually converted into a compound called acetyl-CoA in the mitochondrial matrix. This compound, in turn, undergoes a series of enzymatic reactions under
Hydrogen atoms are chemically very active and therefore immediately react with oxygen diffusing into the mitochondria. The large amount of energy released in this reaction is used to convert many ADP molecules into ATP. These reactions are quite complex and require the participation of a huge number of enzymes that are part of the mitochondrial cristae. On initial stage An electron is removed from a hydrogen atom and the atom becomes a hydrogen ion. The process ends with the addition of hydrogen ions to oxygen. As a result of this reaction, water and a large amount of energy are formed, which is necessary for the operation of ATP synthetase, a large globular protein that protrudes in the form of tubercles on the surface of the mitochondrial cristae. Under the action of this enzyme, which uses the energy of hydrogen ions, ADP is converted into ATP. New ATP molecules are sent from the mitochondria to all parts of the cell, including the nucleus, where the energy of this compound is used to provide a variety of functions.
