Atf adf amp functions. ATP structure and biological role

Nucleoside polyphosphates. All tissues of the body contain moho-, di- and triphosphates of nucleosides in a free state. Adenine-containing nucleotides are especially widely known - adenosine-5-phosphate (AMP), adenosine-5-diphosphate (ADP) and adenosine-5-triphosphate (ATP) (for these compounds, along with the given abbreviations in Latin letters, in the domestic literature abbreviations of the corresponding Russian names are used - AMP, ADP, ATP). Nucleotides such as guanosine triphosphate (GTP), uridine triphosphate (UTP), and cytidine triphosphate (CTP) are involved in a number of biochemical reactions. Their diphosphate forms are designated GDP, UDP and COP, respectively. Nucleoside diphosphates and nucleoside triphosphates are often combined under the term nucleoside polyphosphates. All phosphorylated nucleosides are included in the group of nucleotides, more precisely, mononucleotides.

The importance of mononucleotides is extremely great. Firstly, mononucleotides, especially nucleoside polyphosphates, are coenzymes of many biochemical reactions; they participate in the biosynthesis of proteins, carbohydrates, fats and other substances. Their major role is associated with the presence of a reserve of energy accumulated in their polyphosphate bonds. It is also known that at least some nucleoside polyphosphates, in minute concentrations, have effects on complex functions, such as heart function. Secondly, mononucleotides are structural components of nucleic acids - high-molecular compounds that determine the synthesis of proteins and the transmission of hereditary characteristics (they are studied in biochemistry)

AMP Adenosine Monophosphate

Adenosine Diphosphate (ADP)

Adenosine triphosphate (abbr. ATP, English ATP)

play a vital role in the metabolism and energy, since the addition of phosphate groups to AMP is accompanied by the accumulation of energy (ADP, ATP - high-energy compounds), and their splitting off is the release of energy used for various life processes (see. Bioenergy). Interconversions of ATP, ADP and AMP constantly occur in cells.

12. Proton theory of acids and bases by I. Brønsted and T. Lowry.

According to the Bronsted–Lowry theory,Acids are substances capable of donating a proton (proton donors), and bases are substances that accept a proton (proton acceptors). This approach is known as the proton theory of acids and bases (protolytic theory).

In general, the acid-base interaction is described by the equation:

acid base conjugate conjugate base acid

According to Lewis, acidic and basic properties of organic compounds are assessed by the ability to accept or provide an electron pair with subsequent bond formation. An atom that accepts an electron pair is an electron acceptor, and a compound containing such an atom should be classified as an acid. The atom that provides an electron pair is an electron donor, and the compound containing such an atom is a base.

Lewis acids are electron pair acceptors; Lewis bases are electron pair donors.

13 .Electronic theory of Lewis. “Hard” and “soft” acids and bases.

Acid– a particle with an unfilled outer electron shell, capable of accepting a pair of electrons ( acid= electron acceptor).

Base– particles with a free pair of electrons that can be donated to form a chemical bond ( base= electron donor).

TO acids according to Lewis: molecules formed by atoms with an empty eight-electron shell ( BF3,SO3); complexing cations ( Fe3+,Co2+,Ag+, etc.); halides with unsaturated bonds ( TiCl4,SnCl4); molecules with polarized double bonds ( CO2,SO2) and etc.

TO reasons According to Lewis, they include: molecules containing free electron pairs ( NH3,H2O);anions ( Сl–,F–); organic compounds with double and triple bonds (acetone CH3COCH3); aromatic compounds (aniline С6Н5NH2, phenol C6H5OH).ProtonH+ in Lewis theory it is an acid, (electron acceptor), hydroxide ionOH–– base (electron donor): HO–(↓) + H+ ↔ HO(↓)H.

The interaction between an acid and a base involves the formation of a chemical donor-acceptor bond between reacting particles. The reaction between an acid and a base in general: B(↓)base + Acid↔D(↓)A.

Lewis acids and bases.

According to Lewis's theory, the acid-base properties of compounds are determined by their ability to accept or donate a pair of electrons to form a new bond.

Lewis acids - electron pair acceptors, Lewis's foundations – donors of a pair of electrons.

Lewis acids can be molecules, atoms, or cations that have a vacant orbital and are capable of accepting a pair of electrons to form a covalent bond. Lewis acids include halides of elements of groups II and III of the periodic table, halides of other metals with vacant orbitals, and a proton. Lewis acids participate in reactions as electrophilic reagents.

Lewis bases are molecules, atoms, or anions that have a lone pair of electrons that they provide to form a bond with a vacant orbital. Lewis bases include alcohols, ethers, amines, thioalcohols, thioethers, and compounds with p-bonds. In Lewis reactions, Lewis bases act as nucleophilic species.

The development of Lewis's theory led to the creation of the principle of hard and soft acids and bases (the HMCO principle or the Pearson principle). According to Pearson's principle, acids and bases are divided into hard and soft.

Hard acids - These are Lewis acids whose donor atoms are small in size, have a large positive charge, high electronegativity and low polarizability. These include: proton, metal ions (K +, Na +, Mg 2+, Ca 2+, Al 3+), AlCl 3, etc.

Soft acids - – These are Lewis acids, the donor atoms of which are large in size, highly polarizable, have a small positive charge and low electronegativity. These include: metal ions (Ag +, Cu +), halogens (Br 2, I 2), Br +, I + cations, etc.

Rigid bases – Lewis bases, the donor atoms of which have high electronegativity, low polarizability, and have a small atomic radius. These include: H 2 O, OH -, F -, Cl -, NO 3 -, ROH, NH 3, RCOO - and others.

Soft bases - Lewis bases, the donor atoms of which are highly polarizable, have low electronegativity, and have a large atomic radius. These include: H -, I -, C 2 H 4, C 6 H 6, RS - and others.

The essence of the HMKO principle is that hard acids react with hard bases, soft acids with soft bases

14. Composition, structure and types of isomerism in ethylene hydrocarbons. Physical properties. Polymerization reactions; polymerization reaction mechanisms. Oxidation with oxygen-containing oxidants and biological oxidation.

Composition, structure and types of isomerism in ethylene hydrocarbons

Alkenes, or olefins, ethylene - unsaturated hydrocarbons, in the molecules of which there is one double bond between the carbon atoms. (Slide 3) Alkenes contain fewer hydrogen atoms in their molecule than their corresponding alkanes (with the same number of carbon atoms), therefore such hydrocarbons are called unsaturated or unsaturated. Alkenes form a homologous series with the general formula CnH2n.

The simplest representative of ethylene hydrocarbons, its ancestor is ethylene (ethene) C 2 H 4. The structure of its molecule can be expressed by the following formulas:

By the name of the first representative of this series, such hydrocarbons are called ethylene.

In alkenes, carbon atoms are in the second valence state (sp 2 hybridization). (Slide 4) In this case, a double bond appears between the carbon atoms, consisting of one s-bond and one p-bond. The length and energy of the double bond are 0.134 nm and 610 kJ/mol, respectively. All bond angles of NCH are close to 120º.

Alkenes are characterized by two types of isomerism: structural and spatial. (Slide 5)

Types of structural isomerism:

isomerism of the carbon skeleton

isomerism of double bond position

interclass isomerism

Geometric isomerism is one of the types of spatial isomerism. Isomers in which the same substituents (at different carbon atoms) are located on one side of the double bond are called cis-isomers, and on the opposite side - trans-isomers:

Physical properties
In terms of physical properties, ethylene hydrocarbons are close to alkanes. Under normal conditions, hydrocarbons C 2 -C 4 are gases, C 5 -C 17 are liquids, and higher representatives are solids. Their melting and boiling points, as well as their density, increase with increasing molecular weight. All olefins are lighter than water and poorly soluble in it, but soluble in organic solvents.

Polymerization reactions; polymerization reaction mechanisms.

One of the most practically important reactions of unsaturated compounds (or olefins) is polymerization. The polymerization reaction is the process of formation of a high-molecular compound (polymer) by combining molecules of the original low-molecular compound (monomer) with each other. During polymerization, the double bonds in the molecules of the original unsaturated compound “open”, and due to the free valences formed, these molecules are connected to each other.

Depending on the reaction mechanism, polymerization is of two types:
1) radical, or initiated and
2) ionic, or catalytic.”

“Radical polymerization is caused (initiated) by substances that can decompose into free radicals under reaction conditions - for example, peroxides, as well as by the action of heat and light.
Let's consider the mechanism of radical polymerization.

CH 2 =CH 2 –– R ˙ ® R–CH 2 −CH 2 –– C2H4 ® R−CH 2 −CH 2 −CH 2 −CH 2

At the initial stage, the initiator radical attacks the ethylene molecule, causing homolytic cleavage of the double bond, attaches to one of the carbon atoms and forms a new radical. The resulting radical then attacks the next ethylene molecule and, along the indicated path, leads to a new radical, causing further similar transformations of the original compound.
As can be seen, the growing polymer particle, up to the moment of stabilization, is a free radical. The initiator radical is part of the polymer molecule, forming its final group.

Chain termination occurs either upon a collision with a molecule of a chain growth regulator (it can be a specially added substance that easily donates a hydrogen or halogen atom), or by mutual saturation of the free valences of two growing polymer chains with the formation of one polymer molecule.”

Ionic or catalytic polymerization

“Ionic polymerization occurs due to the formation of reactive ions from monomer molecules. It is from the name of the growing polymer particle during the reaction that the names of polymerization come from - cationic And anionic.

Ionic polymerization (cationic)

Catalysts for cationic polymerization are acids, aluminum and boron chlorides, etc. The catalyst is usually regenerated and is not part of the polymer.
The mechanism of cationic polymerization of ethylene in the presence of an acid as a catalyst can be represented as follows.

CH 2 =CH 2 –– H+ ® CH 3 −CH 2 + –– C2H4 ® CH 3 −CH 2 −CH 2 −C + H 2 etc.

A proton attacks the ethylene molecule, causing the double bond to break, attaching to one of the carbon atoms and forming a carbonium cation or carbocation.
The presented type of decomposition of a covalent bond is called heterolytic cleavage (from Greek heteros - different, different).
The resulting carbocation then attacks the next ethylene molecule and similarly leads to a new carbocation, causing further transformations of the original compound.
As can be seen, the growing polymer particle is a carbocation.
The element cell of polyethylene is represented as follows:

Chain termination can occur due to the capture of the corresponding anion by the growing cation or with the loss of a proton and the formation of a final double bond.

Ionic polymerization (anionic)

Catalysts for anionic polymerization are some organometallic compounds, alkali metal amides, etc.
The mechanism of anionic polymerization of ethylene under the influence of metal alkyls is presented as follows.

CH 2 =CH 2 –– R–M ® - M + –– C2H4 ® - M + etc.

The metal alkyl attacks the ethylene molecule and, under its influence, the metal alkyl dissociates into a metal cation and an alkyl anion. The resulting alkyl anion, causing heterolytic cleavage of the p-bond in the ethylene molecule, attaches to one of the carbon atoms and gives a new carbonium anion or carbanion, stabilized by a metal cation. The resulting carbanion attacks the next ethylene molecule and, along the indicated path, leads to a new carbanion, causing further similar transformations of the original compound into a polymer product with a given degree of polymerization, i.e. with a given number of monomer units.
The growing polymer particle appears to be a carbanion.
The element cell of polyethylene is represented as follows: (CH 2 –CH 2)."

Undoubtedly, the most important molecule in our body in terms of energy production is ATP (adenosine triphosphate: an adenyl nucleotide containing three phosphoric acid residues and produced in mitochondria).

In fact, every cell in our body stores and uses energy for biochemical reactions through ATP, thus ATP can be considered the universal currency of biological energy. All living beings require a continuous supply of energy to support protein and DNA synthesis, metabolism and transport of various ions and molecules, and maintain the vital functions of the body. Muscle fibers during strength training also require readily available energy. As already mentioned, ATP supplies the energy for all these processes. However, in order to form ATP, our cells require raw materials. Humans obtain these raw materials through calories through the oxidation of food consumed. To obtain energy, this food must first be processed into an easily used molecule - ATP.

The ATP molecule must go through several phases before being used.

First, a special coenzyme separates one of the three phosphates (each containing ten calories of energy), releasing large amounts of energy and forming the reaction product adenosine diphosphate (ADP). If more energy is required, the next phosphate group is separated, forming adenosine monophosphate (AMP).

ATP + H 2 O → ADP + H 3 PO 4 + energy
ATP + H 2 O → AMP + H 4 P 2 O 7 + energy

When rapid energy production is not required, the reverse reaction occurs - with the help of ADP, phosphagen and glycogen, the phosphate group is reattached to the molecule, resulting in the formation of ATP. This process involves the transfer of free phosphates to other substances contained in the muscles, which include and. At the same time, glucose is taken from glycogen reserves and broken down.

The energy obtained from this glucose helps convert the glucose back into its original form, after which the free phosphates can again be attached to ADP to form new ATP. Once the cycle is complete, the newly created ATP is ready for next use.

In essence, ATP works like a molecular battery, storing energy when it is not needed and releasing it when it is needed. Indeed, ATP is like a fully rechargeable battery.

ATP structure

The ATP molecule consists of three components:

• Ribose (the same five-carbon sugar that forms the backbone of DNA)
• Adenine (connected carbon and nitrogen atoms)
• Triphosphate

The ribose molecule is located in the center of the ATP molecule, the edge of which serves as a base for adenosine.
A chain of three phosphates is located on the other side of the ribose molecule. ATP saturates the long, thin fibers containing the protein myosin, which forms the basis of our muscle cells.

ATP retention

The average adult's body uses about 200-300 moles of ATP daily (a mole is the chemical term for the amount of substance in a system that contains as many elementary particles as there are carbon atoms in 0.012 kg of the isotope carbon-12). The total amount of ATP in the body at any given moment is 0.1 mole. This means that ATP must be reused 2000-3000 times throughout the day. ATP cannot be stored, so the level of its synthesis almost matches the level of consumption.

ATP systems

Because ATP is important from an energy standpoint, and because of its widespread use, the body has different ways of producing ATP. These are three different biochemical systems. Let's look at them in order:

When the muscles have a short but intense period of activity (about 8-10 seconds), the phosphagen system is used - ATP combines with creatine phosphate. The phosphagen system ensures that small amounts of ATP are constantly circulating in our muscle cells.

Muscle cells also contain a high-energy phosphate, creatine phosphate, which is used to restore ATP levels after short-term, high-intensity activity. The enzyme creatine kinase takes the phosphate group from creatine phosphate and quickly transfers it to ADP to form ATP. So, the muscle cell converts ATP to ADP, and phosphagen quickly reduces ADP to ATP. Creatine phosphate levels begin to decline after just 10 seconds of high-intensity activity, and energy levels drop. An example of how the phosphagen system works is, for example, the 100-meter sprint.

The glycogen-lactic acid system supplies energy to the body at a slower pace than the phosphagen system, although it works relatively quickly and provides enough ATP for about 90 seconds of high-intensity activity. In this system, lactic acid is produced from glucose in muscle cells through anaerobic metabolism.

Given the fact that in the anaerobic state the body does not use oxygen, this system provides short-term energy without activating the cardiorespiratory system in the same way as the aerobic system, but with time savings. Moreover, when in anaerobic mode the muscles work quickly, contract powerfully, they block the supply of oxygen, since the vessels are compressed.

This system is also sometimes called anaerobic respiration, and a good example in this case is the 400-meter sprint.

If physical activity lasts more than a few minutes, the aerobic system comes into play, and the muscles receive ATP first from, then from fats and finally from amino acids (). Protein is used for energy mainly in conditions of famine (dieting in some cases).

Aerobic respiration produces the slowest amount of ATP, but produces enough energy to sustain physical activity for several hours. This occurs because during aerobic respiration, glucose is broken down into carbon dioxide and water without being counteracted by lactic acid in the glycogen-lactic acid system. Glycogen (the stored form of glucose) during aerobic respiration comes from three sources:

1. Absorption of glucose from food in the gastrointestinal tract, which enters the muscles through the circulatory system.
2. Glucose residues in muscles
3. The breakdown of liver glycogen into glucose, which enters the muscles through the circulatory system.

Conclusion

If you've ever wondered where we get the energy to perform different activities under different conditions, the answer is mostly ATP. This complex molecule assists in converting various food components into easily usable energy.

Without ATP, our body simply would not be able to function. Thus, the role of ATP in energy production is multifaceted, but at the same time simple.

The figure shows two methods ATP structure images. Adenosine monophosphate (AMP), adenosine diphosphate (ADP), and adenosine triphosphate (ATP) belong to a class of compounds called nucleotides. The nucleotide molecule consists of a five-carbon sugar, a nitrogenous base and phosphoric acid. In the AMP molecule, the sugar is represented by ribose, and the base is adenine. There are two phosphate groups in the ADP molecule, and three in the ATP molecule.

ATP value

When ATP is broken down into ADP and inorganic phosphate (Pn) energy is released:

The reaction occurs with the absorption of water, i.e. it represents hydrolysis (in our article we have encountered this very common type of biochemical reactions many times). The third phosphate group split off from ATP remains in the cell in the form of inorganic phosphate (Pn). The free energy yield for this reaction is 30.6 kJ per 1 mol of ATP.

From ADF and phosphate, ATP can be synthesized again, but this requires spending 30.6 kJ of energy per 1 mole of newly formed ATP.

In this reaction, called a condensation reaction, water is released. The addition of phosphate to ADP is called the phosphorylation reaction. Both equations above can be combined:

This reversible reaction is catalyzed by an enzyme called ATPase.

All cells, as already mentioned, need energy to perform their work, and for all cells of any organism the source of this energy is serves as ATP. Therefore, ATP is called the “universal energy carrier” or “energy currency” of cells. An appropriate analogy is electric batteries. Remember why we don’t use them. With their help, in one case we can receive light, in another case sound, sometimes mechanical movement, and sometimes we need actual electrical energy from them. The convenience of batteries is that we can use the same energy source - a battery - for a variety of purposes, depending on where we place it. ATP plays the same role in cells. It supplies energy for such diverse processes as muscle contraction, transmission of nerve impulses, active transport of substances or protein synthesis, and all other types of cellular activity. To do this, it must simply be “connected” to the corresponding part of the cell apparatus.

The analogy can be continued. Batteries must first be manufactured, and some of them (rechargeable ones), just like , can be recharged. When batteries are manufactured in a factory, a certain amount of energy must be stored in them (and thereby consumed by the factory). ATP synthesis also requires energy; its source is the oxidation of organic substances during respiration. Since energy is released during the process of oxidation to phosphorylate ADP, such phosphorylation is called oxidative phosphorylation. During photosynthesis, ATP is produced from light energy. This process is called photophosphorylation (see Section 7.6.2). There are also “factories” in the cell that produce most of the ATP. These are mitochondria; they contain chemical “assembly lines” on which ATP is formed during aerobic respiration. Finally, the discharged “batteries” are also recharged in the cell: after ATP, having released the energy contained in it, is converted into ADP and Fn, it can be quickly synthesized again from ADP and Fn due to the energy received in the process of respiration from the oxidation of new portions of organic matter.

ATP quantity in the cell at any given moment is very small. Therefore, in ATF one should see only the carrier of energy, and not its depot. Substances such as fats or glycogen are used for long-term energy storage. Cells are very sensitive to ATP levels. As the rate of its use increases, the rate of the breathing process that maintains this level also increases.

Role of ATP as a connecting link between cellular respiration and processes involving energy consumption, is visible from the figure. This diagram looks simple, but it illustrates a very important pattern.

It can therefore be said that, in general, the function of breathing is to produce ATP.

Let us briefly summarize what was said above.
1. The synthesis of ATP from ADP and inorganic phosphate requires 30.6 kJ of energy per 1 mole of ATP.
2. ATP is present in all living cells and is therefore a universal carrier of energy. No other energy carriers are used. This simplifies the matter - the necessary cellular apparatus can be simpler and work more efficiently and economically.
3. ATP easily delivers energy to any part of the cell to any process that requires energy.
4. ATP quickly releases energy. This requires only one reaction - hydrolysis.
5. The rate of ATP production from ADP and inorganic phosphate (respiration process rate) is easily adjusted according to needs.
6. ATP is synthesized during respiration due to chemical energy released during the oxidation of organic substances such as glucose, and during photosynthesis due to solar energy. The formation of ATP from ADP and inorganic phosphate is called the phosphorylation reaction. If the energy for phosphorylation is supplied by oxidation, then we speak of oxidative phosphorylation (this process occurs during respiration), but if light energy is used for phosphorylation, then the process is called photophosphorylation (this occurs during photosynthesis).

ATP (adenosine triphosphate)– an organic compound from the group of nucleoside triphosphates, which plays a major role in a number of biochemical processes, primarily in providing cells with energy.

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Structure and synthesis of ATP

Adenosine triphosphate is adenine to which three molecules of orthophosphoric acid are attached. Adenine is part of many other compounds that are widespread in living nature, including nucleic acids.

The release of energy, which is used by the body for a variety of purposes, occurs through the process of ATP hydrolysis, leading to the appearance of one or two free molecules of phosphoric acid. In the first case, adenosine triphosphate is converted into adenosine diphosphate (ADP), in the second, into adenosine monophosphate (AMP).

ATP synthesis, which occurs in a living organism due to the combination of adenosine diphosphate with phosphoric acid, can occur in several ways:

1. Main: oxidative phosphorylation, which occurs in intracellular organelles - mitochondria, during the oxidation of organic substances.
2. The second pathway: substrate phosphorylation, which occurs in the cytoplasm and plays a central role in anaerobic processes.

Functions of ATP

Adenosine triphosphate does not play any significant role in energy storage, but rather performs transport functions in cellular energy metabolism. Adenosine triphosphate is synthesized from ADP and is soon converted back to ADP, releasing useful energy.

In relation to vertebrates and humans, the main function of ATP is to ensure the motor activity of muscle fibers.

Depending on the duration of the effort, whether it is short-term work or long-term (cyclic) load, the energy processes are quite different. But in all of them, adenosine triphosphate plays a crucial role.

ATP structural formula:

In addition to its energy function, adenosine triphosphate plays a significant role in signal transmission between nerve cells and other intercellular interactions, in the regulation of the action of enzymes and hormones. It is one of the starting products for protein synthesis.

How many ATP molecules are produced during glycolysis and oxidation?

The lifetime of one molecule is usually no more than a minute, so at any given moment the content of this substance in the body of an adult is about 250 grams. Despite the fact that the total amount of adenosine triphosphate synthesized per day is usually comparable to the body’s own weight.

The process of glycolysis occurs in 3 stages:

1. Preparatory.
   At the entrance to this stage, adenosine triphosphate molecules are not formed
2. Anaerobic.
   2 ATP molecules are formed.
3. Aerobic.
   During it, oxidation of PVC and pyruvic acid occurs. 36 ATP molecules are formed from 1 glucose molecule.

In total, during the glycolysis of 1 glucose molecule, 38 ATP molecules are formed: 2 during the anaerobic stage of glycolysis, 36 during the oxidation of pyruvic acid.