Anabolism and catabolism - energy metabolism and the relationship of processes in the body

Metabolism concept

Metabolism can be defined as a set of biochemical processes occurring in any living organism, including the human body. Metabolism is needed to ensure the vital functions of organs and systems, and these chemical reactions allow us to grow, adapt to environmental conditions, heal wounds, reproduce, etc. Metabolic processes are divided into two types:

• assimilation (constructive processes or anabolism);
• dissimilation (destructive processes or catabolism).

Fermentation

Main article: Fermentation (biochemistry)

Even if oxygen is absent, glycolysis can continue to generate ATP. However, for glycolysis to continue producing ATP, NAD+ must be present, which is responsible for the oxidation of glucose. This is achieved by recycling NADH back to NAD+. When NAD+ is reduced to NADH, NADH's electrons are eventually transferred to a separate organic molecule, converting NADH back to NAD+. This process of replenishing NAD+ is called fermentation and is divided into two categories.[3]

Alcoholic fermentation

In alcoholic fermentation, when a glucose molecule is oxidized, ethyl alcohol (ethyl alcohol) and carbon dioxide are byproducts. In the organic molecule, pyruvate from glycolysis is responsible for the resumption of NAD + supply in this type of fermentation. Each pyruvate releases a molecule of carbon dioxide, turning into acetaldehyde. Acetaldehyde is then reduced by NADH produced by glycolysis to form waste alcohol, ethanol, and to form NAD+, thereby replenishing it for glycolysis to continue producing ATP.[3]

Lactic fermentation

In lactic acid fermentation, each pyruvate molecule is directly reduced by NADH. The only byproduct of this type of fermentation is lactate. Fermentation of lactic acid is used by human muscle cells as a means of producing ATP during strenuous exercise where oxygen consumption is higher than oxygen supplied. As this process progresses, excess lactate is taken to the liver, which converts it back to pyruvate.[3]

What is anabolism

Plastic exchange is possible only if there is a sufficient amount of energy. Anabolism is the process of formation of new cells, structures, tissues, organic substances in the body. The creation of particles is accompanied by the absorption of energy, while all processes occur at rest and are stimulated by anabolic hormones (steroids, insulin, growth hormone, etc.) Anabolism contributes to:

• muscle growth/development;
• bone mineralization;
• restoration of tissues and cells.

Stages of energy metabolism

Despite the complexity of energy exchange reactions, it is divided into three phases:

1. preparatory,
2. anaerobic (without oxygen),
3. aerobic (oxygen).

At the preparatory stage, molecules of glycans, lipids, proteins, and nucleic acids are decomposed into simpler ones, for example, glucose, glycerol and fatty acids, amino acids, and nucleotides. This phase can take place directly in the cells or in the intestines, from where these substances are transported by the bloodstream.

In the anaerobic phase of energy catabolism, the monomers of organic compounds are further broken down into simpler intermediate compounds, for example, pyruvic acid or pyruvate. It does not require the presence of oxygen, and for organisms living in swamp mud, this is the only way to obtain energy. The anaerobic phase of energy metabolism takes place in the cytoplasm.

Some substances undergo oxygen-free breakdown, while glucose most often remains the main substrate of the reactions. The process of its oxygen-free breakdown is usually called glycolysis. Due to glycolysis, a glucose molecule loses four hydrogen atoms, that is, it is oxidized, and two molecules of pyruvic acid, two molecules of ATP and two molecules of the hydrogen carrier reduced by NADH + H + are formed:

C6H12O6+2H3PO4+2ADP+2NAD

→
2C3H4O3+2ATP+2NADH+H++2H2O.
The formation of ATP from ADP occurs due to the direct transfer of phosphate anion from pre-phosphorylated sugar and is called substrate phosphorylation.

The aerobic phase of energy catabolism can only occur in the presence of oxygen, while intermediate products formed during anoxic decomposition are oxidized to the final products (carbon dioxide and water), and most of the energy stored in the chemical bonds of organic compounds is released. The ATP molecule contains 36 high-energy bonds. This stage is called tissue respiration. When oxygen is absent, metabolic intermediate products are converted into certain organic substances; this process is usually called fermentation or fermentation.

What is catabolism

The stages of this process are carried out with the formation of energy (at the same time, ATP synthesis occurs in the ETC - the electron transport chain). Catabolism is energy exchange, the opposite of anabolism, which is characterized by the breakdown of tissues, organ structures, and complex substances into simple elements. The most important task of the process is to provide the body with the necessary energy and further use it for the needs of the body. Catabolism is caused by:

• stress;
• starvation;
• physical activity, other factors that are accompanied by the production of adrenaline.

How to slow down?

Considering the specific and general pathways of catabolism, we can conclude that it is impossible to stop catabolism. At the same time, you can look for ways to slow it down.

The rate of catabolism is directly related to the rate of metabolism. Despite the fact that people think that a slow metabolism leads to weight gain and leads to catabolism, this is not entirely true. Therefore, if your goal is to slow down catabolism, there are 3 main ways:

1. Increase the time of anabolic processes.
2. Reduce stress on the body.
3. Slow down metabolism.

To increase anabolic processes, you need to constantly feed the body with energy and builders.

That is why experienced bodybuilders eat 5-8 times a day, strictly at certain times.

To increase the time of anabolic processes, you need to eat hard-to-digest foods (complex carbohydrates, rich in fiber), and consume at least 2 grams of protein per kilogram of net weight.

Reducing stressful situations for the body is easier to achieve. Don't move, sleep and feel joyful emotions. A day off/vacation/break between workouts can help with this. 8 hours sleep, and a bar of dark dark chocolate.

Slowing down metabolism is extremely easy to achieve - you just need to create a situation in which metabolic processes slow down extremely. A good way is to sleep a lot. A bad way is to stop eating.

The relationship between anabolism and catabolism

Both processes are interrelated and equally important for humans; they underlie metabolism. At the same time, energy metabolism serves as the basis for any biochemistry occurring in the body. Every life process will be impossible without metabolism: thanks to the transformation of energy and substances in the body, cells can grow, maintain their structure and develop, creating complex structures.

The relationship between anabolism and catabolism is undeniable, although the two processes are radically opposite to each other. As a result of catabolic reactions, energy and substances are produced that are necessary for the anabolic process. At the same time, anabolism ensures the production of enzymes and other products necessary for catabolism. For example, the human body can independently compensate for the lack of fourteen amino acids (constituent components of proteins). An imbalance of metabolic processes can lead to the death of the entire organism.

What is the connection between sleep and anabolism?

Sleep is a complex neurophysiological process. There are many effects that sleep has on the human condition, but they are not the subject of this article. Here we will consider only the association of the process of anabolism and sleep.

At night, when the brain is immersed in sleep, the body works “more economically” - the pulse and heart rate slow down. Night is the kingdom of the Vagus or vagus nerve - that part of the nervous system that belongs to the parasympathetic. This means that the processes of digestion and assimilation of food within the small intestine are more efficient. This is a plus for anabolism. In addition, inflammatory processes intensify and become more intense. This means that we quickly reach the third, desired phase of the inflammatory process.

The process of anabolism is caused not only by sex hormones. Somatotropin, also known as growth hormone, plays an important role in this process. And the time when it is released in greatest quantity is at night.

Conclusion: sleep has a very positive effect on the anabolism process.

© edesignua — depositphotos.com. Circadian rhythms

What happens during catabolism

With the help of energy exchange, the body obtains energy through the destruction of biological materials. During catabolism, the process of breaking down large complexes of molecules into smaller ones occurs, and the energy that is needed for the healthy functioning of organs and systems occurs. Thanks to catabolism, the body receives strength for any physical activity - from the cellular level to movement of the entire body. During catabolic reactions, large polymers are broken down into simple monomers - the building units from which they are formed. Example of catabolism:

1. There is a violation of the integrity of nucleic acids responsible for the transmission of genetic information, as a result of which they break down into nucleotides. Nucleic acids are divided into pentose, purines, and pyrimidines.
2. Polysaccharides are converted into monosaccharides through the process of catabolism. Substances (complex carbohydrates) such as cellulose, starch or glycogen belong to the group of polysaccharides. If they are destroyed, the body will receive simple or fast carbohydrates - ribose, glucose, fructose (a group of substances called monosaccharides).
3. When proteins break down, amino acids are released. These substances, formed as a result of catabolism, can be reused in anabolic reactions, converted into other chemical compounds, or participate in the synthesis of other amino acids. Sometimes proteins break down into amino acids necessary for the synthesis of glucose that enters the blood.

Stages of catabolism

This process is necessary for the body to receive sufficient energy. Any substances processed in the human body are sources of ATP - special molecules necessary for energy storage. The amount of adenosine triphosphate is limited, so it must be constantly replenished and this can only be done through catabolism. Energy exchange occurs in several stages. Stages of catabolism:

• carbohydrates, proteins, fats break down into simple molecules in the gastrointestinal tract, outside the cell;
• molecules enter the cell, resulting in energy accumulation (oxygen-free stage);
• The catabolic processes are completed with the formation of carbon dioxide, large amounts of energy and water.

Metabolism and energy in the cell. Photosynthesis, chemosynthesis. Assimilation process (basic reactions).

The cell constantly exchanges substances and energy with the environment. Metabolism (metabolism)

- the main property of living organisms. At the cellular level, metabolism includes two processes: assimilation (anabolism) and dissimilation (catabolism). These processes occur simultaneously in the cell.

Assimilation (plastic exchange) is a set of reactions of biological synthesis. From simple substances entering the cell from the outside, substances characteristic of a given cell are formed. The synthesis of substances in the cell occurs using the energy contained in ATP molecules.

Dissimilation (energy metabolism) is a set of reactions of the breakdown of substances. When high-molecular compounds are broken down, the energy required for biosynthesis reactions is released.

According to the type of assimilation, organisms can be autotrophic, heterotrophic and mixotrophic.

Photosynthesis and chemosynthesis are two forms of plastic metabolism. Photosynthesis is the process of formation of organic substances from carbon dioxide and water in the light with the participation of photosynthetic pigments.

Chemosynthesis is a method of autotrophic nutrition in which the source of energy for the synthesis of organic substances from CO2 is the oxidation reactions of inorganic compounds

Typically, all organisms capable of synthesizing organic substances from inorganic substances, i.e. Organisms capable of photosynthesis and chemosynthesis are classified as autotrophs. Autotrophs traditionally include plants and some microorganisms.

The main substance involved in the multi-stage process of photosynthesis is chlorophyll. It is this that transforms solar energy into chemical energy.

Light phase of photosynthesis:

(carried out on thylakoid membranes)

Light hitting a chlorophyll molecule is absorbed by it and brings it into an excited state - the electron that is part of the molecule, having absorbed the energy of light, moves to a higher energy level and participates in synthesis processes;

Under the influence of light, splitting (photolysis) of water also occurs: protons (with the help of electrons) are converted into hydrogen atoms and spent on the synthesis of carbohydrates;

ATP (energy) is synthesized

Dark phase of photosynthesis (occurs in the stroma of chloroplasts)

the actual synthesis of glucose and the release of oxygen

Please note : this phase is called dark not because it occurs at night - glucose synthesis occurs, in general, around the clock, but the dark phase no longer requires light energy.

20. Metabolism in the cell. The process of dissimilation. The main stages of energy metabolism.

In all cells of living organisms, processes of metabolism and energy continuously occur - this is metabolism. If we consider this process in more detail, then these are constant processes of formation and decay of substances and absorption and release of energy.

Metabolism in the cell:

The process of synthesis of substances = plastic metabolism = assimilation = anabolism

To build something, you need to expend energy - this process occurs with the absorption of energy.

Breakdown process = energy metabolism = dissimilation = catabolism

This is a process in which complex substances are decomposed into simpler ones, and energy is released.

Basically, these are oxidation reactions, they occur in mitochondria, the simplest example is respiration . During respiration, complex organic substances are broken down into simpler ones, releasing carbon dioxide and energy. In general, these two processes are interconnected and transform into one another. In total, the equation of metabolism - metabolism in the cell - can be written as follows: catabolism + anabolism = metabolism in the cell = metabolism.

The processes of creation are constantly going on in the cell. More complex substances are formed from simple substances, and high molecular weight substances are formed from low molecular ones. Proteins, complex carbohydrates, fats, and nucleic acids are synthesized. Synthesized substances are used to build different parts of the cell, its organelles, secretions, enzymes, and reserve substances. Synthetic reactions are especially intense in a growing cell; substances are constantly being synthesized to replace molecules that are used up or destroyed when damaged. Each destroyed molecule of protein or some other substance is replaced by a new molecule. In this way, the cell maintains its shape and chemical composition constant, despite their continuous change in the process of life.

The synthesis of substances that occurs in a cell is called biological synthesis or biosynthesis for short. All biosynthesis reactions involve the absorption of energy. The set of biosynthesis reactions is called plastic metabolism or assimilation (Latin “similis” - similar). The meaning of this process is that food substances entering the cell from the external environment, which are sharply different from the cell substance, become cell substances as a result of chemical transformations.

Cleavage reactions. Complex substances break down into simpler ones, and high-molecular substances into low-molecular ones. Proteins break down into amino acids, starch into glucose. These substances are broken down into even lower molecular weight compounds, and in the end very simple, energy-poor substances are formed - CO2 and H2O. Fission reactions are in most cases accompanied by the release of energy.

The biological significance of these reactions is to provide the cell with energy. Any form of activity - movement, secretion, biosynthesis, etc. - requires energy expenditure. The set of cleavage reactions is called cellular energy metabolism or dissimilation. Dissimilation is the exact opposite of assimilation: as a result of splitting, substances lose their resemblance to cell substances.

Plastic and energy exchanges (assimilation and dissimilation) are inextricably linked. On the one hand, biosynthesis reactions require the expenditure of energy, which is drawn from cleavage reactions. On the other hand, to carry out energy metabolism reactions, constant biosynthesis of enzymes servicing these reactions is necessary, since during operation they wear out and are destroyed. The complex systems of reactions that make up the process of plastic and energy exchanges are closely connected not only with each other, but also with the external environment.

Food substances enter the cell from the external environment, which serve as material for plastic exchange reactions, and in splitting reactions they release the energy necessary for the functioning of the cell. Substances that can no longer be used by the cell are released into the external environment. The totality of all enzymatic reactions of the cell, i.e., the totality of plastic and energy exchanges (assimilation and dissimilation) connected with each other and with the external environment, is called metabolism and energy. This process is the main condition for maintaining the life of the cell, the source of its growth, development and functioning.

Energy exchange. The body needs energy to function. Plants accumulate solar energy in organic matter during photosynthesis. In the process of energy metabolism, organic substances are broken down and the energy of chemical bonds is released. Partially it is dissipated in the form of heat, and partially stored in ATP molecules. In animals, energy metabolism occurs in three stages.

The first stage is preparatory. Food enters the body of animals and humans in the form of complex high-molecular compounds. Before entering cells and tissues, these substances must be broken down into low-molecular substances that are more accessible for cellular absorption. At the first stage, hydrolytic breakdown of organic substances occurs, which occurs with the participation of water. It occurs under the action of enzymes in the digestive tract of multicellular animals, in the digestive vacuoles of unicellular animals, and at the cellular level in lysosomes. Preparatory stage reactions:

proteins + H20 -> amino acids + Q;

fats + H20 -> glycerol + higher fatty acids + Q;

polysaccharides -> glucose + Q.

In mammals and humans, proteins are broken down into amino acids in the stomach and duodenum under the action of enzymes - peptide hydrolases (pepsin, trypsin, chemotrypsin). The breakdown of polysaccharides begins in the oral cavity under the action of the enzyme ptyalin, and then continues in the duodenum under the action of amylase. Fats are also broken down there by the action of lipase. All energy released in this case is dissipated in the form of heat. The resulting low-molecular substances enter the blood and are delivered to all organs and cells. In cells they enter the lysosome or directly into the cytoplasm. If cleavage occurs at the cellular level in lysosomes, the substance immediately enters the cytoplasm. At this stage, substances are prepared for intracellular breakdown.

The second stage is oxygen-free oxidation. The second stage is carried out at the cellular level in the absence of oxygen. It occurs in the cytoplasm of the cell. Let's consider the breakdown of glucose as one of the key metabolic substances in the cell. All other organic substances (fatty acids, glycerol, amino acids) are drawn into the processes of its transformation at different stages. The oxygen-free breakdown of glucose is called glycolysis.

Glucose undergoes a series of successive transformations (Fig. 16). First, it is converted into fructose, phosphorylated - activated by two ATP molecules and converted into fructose diphosphate. Next, the six-carbon carbohydrate molecule breaks down into two three-carbon compounds - two molecules of glycerophosphate (triose). After a series of reactions, they are oxidized, losing two hydrogen atoms each, and are converted into two molecules of pyruvic acid (PVA). As a result of these reactions, four ATP molecules are synthesized. Since two ATP molecules were initially spent on activating glucose, the total result is 2 ATP. Thus, the energy released during the breakdown of glucose is partially stored in two ATP molecules, and partially consumed in the form of heat. The four hydrogen atoms that were removed during the oxidation of glycerophosphate combine with the hydrogen carrier NAD+ (nicotinamide dinucleotide phosphate). It is the same hydrogen carrier as NADP+, but is involved in energy metabolism reactions.

Generalized scheme of glycolysis reactions:

C6H1206 + 2NAD+—

> 2С3Н403 + 2NAD•2H

2ADF —

> 2ATP

The reduced NAD•2H molecules enter the mitochondria, where they are oxidized, releasing hydrogen. Depending on the type of cell, tissue or organism, pyruvic acid in an oxygen-free environment can be further converted into lactic acid, ethyl alcohol, butyric acid or other organic substances. In anaerobic organisms, these processes are called fermentation.

Lactic acid fermentation:

C6H1206 + 2NAD+ -> 2C3H403 + 2NAD•2H <=> 2C3H603 + 2NAD+

Glucose PVC lactic acid

Alcoholic fermentation:

C6H1206 + 2NAD+ -> 2C3H403 + 2NAD•2H <=> 2C2H5OH + 2C02 + 2NAD+

Glucose PVC ethyl alcohol

The third stage is biological oxidation, or respiration. This stage occurs only in the presence of oxygen and is otherwise called oxygen.

It occurs in mitochondria.
Pyruvic acid from the cytoplasm enters the mitochondria, where it loses a molecule of carbon dioxide and is converted into acetic acid, combining with the activator and carrier coenzyme-A. The resulting acetyl-CoA then enters into a series of cyclic reactions. The products of oxygen-free decomposition - lactic acid, ethyl alcohol - also further undergo changes and undergo oxidation with oxygen. Lactic acid is converted into pyruvic acid if it is formed due to a lack of oxygen in animal tissues. Ethyl alcohol is oxidized to acetic acid and binds to CoA. Cyclic reactions in which acetic acid is converted are called the cycle of di- and tricarboxylic acids,
or
the Krebs cycle,
named after the scientist who first described these reactions. As a result of a series of sequential reactions, decarboxylation occurs - the removal of carbon dioxide and oxidation - the removal of hydrogen from the resulting substances. Carbon dioxide, formed during decarboxylation of PVC and in the Krebs cycle, is released from mitochondria, and then from the cell and body during respiration. Thus, carbon dioxide is formed directly during the decarboxylation of organic substances. All the hydrogen that is removed from the intermediate substances combines with the NAD+ transporter, and NAD•2H is formed. During photosynthesis, carbon dioxide combines with intermediate substances and is reduced with hydrogen. Here the process is reversed.

The general equation for the decarboxylation and oxidation of PVC is:

2С3Н403 + 6Н20 + 10NAD+ -> 6С02 + 10NAD• N.

Let us now trace the path of the NAD•2H molecules. They arrive at the cristae of mitochondria, where the respiratory chain of enzymes is located. On this chain, hydrogen is abstracted from the carrier with the simultaneous removal of electrons. Each molecule of reduced NAD•2H donates two hydrogens and two electrons. The energy of the removed electrons is very high. They enter the respiratory chain of enzymes, which consists of proteins - cytochromes. Moving through this system in cascade, the electron loses energy. Due to this energy, ATP molecules are synthesized in the presence of the enzyme ATPase. Simultaneously with these processes, hydrogen ions are pumped through the membrane to its outer side. In the process of oxidation of 12 molecules of NAD-2H, which were formed during glycolysis (2 molecules) and as a result of reactions in the Krebs cycle (10 molecules), 36 ATP molecules are synthesized. The synthesis of ATP molecules coupled with the process of hydrogen oxidation is called oxidative phosphorylation.

The final electron acceptor is the oxygen molecule that enters the mitochondria during respiration. Oxygen atoms on the outside of the membrane accept electrons and become negatively charged. Positive hydrogen ions combine with negatively charged oxygen to form water molecules. Let us remember that atmospheric oxygen is formed as a result of photosynthesis during the photolysis of water molecules, and hydrogen is used to reduce carbon dioxide. In the process of energy exchange, hydrogen and oxygen are recombined and converted into water.

Generalized reaction of the oxygen stage of oxidation:

2С3Н403 + 4Н + 602 -> 6С02 + 6Н20;

36ADP -> 36ATP.

So, the yield of ATP molecules during oxygen oxidation is 18 times greater than during oxygen-free oxidation.

The overall equation for glucose oxidation in two stages:

С6Н1206 + 602 —> 6С02 + 6Н20 + E

—>
Q
(heat).

\

38ADP —> 38ATP

Thus, during the breakdown of glucose in two stages, a total of 38 ATP molecules are formed, with the main part - 36 molecules - during oxygen oxidation. This energy gain ensured the preferential development of aerobic organisms compared to anaerobic ones.

21. Mitotic cell cycle. Characteristics of periods. Mitosis, its biological significance. Amitosis.

The cell (life) cycle refers to the existence of a cell from the moment of its appearance as a result of division until another division or until the death of the cell.

A concept close to it is the mitotic cycle.

The mitotic cycle is the life activity of a cell from division to the next division.

It is a complex of interrelated and coordinated phenomena during cell division, as well as before and after it. Mitotic cycle

- this is a set of processes occurring in a cell from one division to the next and ending with the formation of two cells of the next generation. In addition, the concept of the life cycle also includes the period during which the cell performs its functions and periods of rest. At this time, the further cell fate is uncertain: the cell may begin to divide (enters mitosis) or begin to prepare to perform specific functions.

Main stages of mitosis.

1. Reduplication (self-duplication) of the genetic information of the mother cell and its uniform distribution between daughter cells. This is accompanied by changes in the structure and morphology of chromosomes, in which more than 90% of the information of a eukaryotic cell is concentrated.

2. The mitotic cycle consists of four consecutive periods: presynthetic (or postmitotic) G1, synthetic S, postsynthetic (or premitotic) G2 and mitosis itself. They constitute the autocatalytic interphase (preparatory period).

Cell cycle phases:

1) presynthetic (G1) (2n2c, where n is the number of chromosomes, c is the number of molecules). Occurs immediately after cell division. DNA synthesis has not yet occurred. The cell is actively growing in size, storing substances necessary for division: proteins (histones, structural proteins, enzymes), RNA, ATP molecules. Division of mitochondria and chloroplasts (i.e., structures capable of self-reproduction) occurs. The organizational features of the interphase cell are restored after the previous division;

2) synthetic (S) (2n4c). Genetic material is duplicated through DNA replication. It occurs in a semi-conservative manner, when the double helix of the DNA molecule diverges into two chains and a complementary chain is synthesized on each of them.

The result is two identical DNA double helices, each consisting of one new and one old DNA strand. The amount of hereditary material doubles. In addition, the synthesis of RNA and proteins continues. Also, a small part of mitochondrial DNA undergoes replication (the main part of it is replicated in the G2 period);

3) postsynthetic (G2) (2n4c). DNA is no longer synthesized, but the defects made during its synthesis in the S period are corrected (repair). Energy and nutrients are also accumulated, and the synthesis of RNA and proteins (mainly nuclear) continues.

S and G2 are directly related to mitosis, so they are sometimes separated into a separate period - preprophase.

After this, mitosis proper occurs, which consists of four phases. The division process includes several successive phases and is a cycle. Its duration varies and ranges from 10 to 50 hours in most cells. In human body cells, the duration of mitosis itself is 1–1.5 hours, the G2 period of interphase is 2–3 hours, and the S period of interphase is 6–10 hours. .

Stages of mitosis.

The process of mitosis is usually divided into four main phases: prophase, metaphase, anaphase

and
telophase
. Since it is continuous, the change of phases is carried out smoothly - one imperceptibly passes into the other.

In prophase , the volume of the nucleus increases, and due to the spiralization of chromatin, chromosomes are formed. By the end of prophase, it is clear that each chromosome consists of two chromatids. The nucleoli and nuclear membrane gradually dissolve, and the chromosomes appear randomly located in the cytoplasm of the cell. Centrioles diverge towards the poles of the cell. An achromatin fission spindle is formed, some of the threads of which go from pole to pole, and some are attached to the centromeres of the chromosomes. The content of genetic material in the cell remains unchanged (2n4c).

In metaphase, chromosomes reach maximum spiralization and are arranged in an orderly manner at the equator of the cell, so they are counted and studied during this period. The content of genetic material does not change (2n4c).

In anaphase, each chromosome “splits” into two chromatids, which are then called daughter chromosomes. The spindle strands attached to the centromeres contract and pull the chromatids (daughter chromosomes) toward opposite poles of the cell. The content of genetic material in the cell at each pole is represented by a diploid set of chromosomes, but each chromosome contains one chromatid (4n4c).

In telophase, the chromosomes located at the poles despiral and become poorly visible. Around the chromosomes at each pole, a nuclear membrane is formed from membrane structures of the cytoplasm, and nucleoli are formed in the nuclei. The fission spindle is destroyed. At the same time, the cytoplasm is dividing. Daughter cells have a diploid set of chromosomes, each of which consists of one chromatid (2n2c).

What happens during the process of anabolism

During energy exchange, matter is created and energy is consumed. As a result of anabolic reactions, complex substances are created. During anabolism, new cells are created and homeostasis of all living tissues of the body is maintained. The body's action is aimed at creating more complex molecules from simple units. The mechanism of anabolic reactions is characterized by the use of several simple substances to synthesize many different end products. Examples of anabolic effects are:

• nutrition of bone tissue for their growth, restoration, development;
• increase in muscle mass;
• wound healing;
• growth of nails, hair, etc.

Due to anabolic processes, monomers are converted into polymers - large molecules with a complex structure, including many miniature building units that are similar to each other. For example: amino acids (monomers) as a result of a series of anabolic chemical reactions form proteins, which are large complex molecules with a three-dimensional structure (polymers).

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The meaning of anabolism and catabolism

Energy metabolic reactions play a very important role for humans, and the body can maintain its normal state only if anabolism and catabolism are in balance. When one of the bioprocesses is suppressed, a violation of the second is inevitable, since they are closely related. An imbalance of energy metabolism can cause various diseases, hormonal imbalances and, as a result, a strong gain of fat, or the reverse process will start and excessive weight loss will occur.

Catabolism is responsible for breaking down muscle tissue and other elements to produce energy. The reaction is triggered during stress, poor sleep, sports training, fatigue, hunger. At the same time, the body produces the hormone cortisol, which destroys muscles, thereby activating the accumulation of fat and increasing glucose levels. These phenomena are extremely undesirable for athletes. However, cortisol also has a positive effect on the body: it breaks down muscle amino acids, which is extremely important for human life.

The importance of anabolism and catabolism for human life cannot be overestimated. If you try to artificially suppress catabolic reactions, hormonal imbalances are likely to develop, so you should learn to adhere to the correct daily routine and control muscle development. This can be achieved if you provide your body with proper rest, lead a healthy lifestyle, choose a balanced diet and competently create a training program. In addition, experts advise athletes to use dietary supplements and vitamins.

The essence

Catabolism is a direct component of metabolic processes in the body. What is she like? It’s very simple – it’s resource optimization. Our body works like a pendulum, constantly creating new cells and destroying old ones. In fact, in 5 years you are completely renewed, being a different person. But that's not all.

In a biochemical understanding, catabolism is the breakdown of complex substances into simpler ones or the oxidation of various molecules. The process occurs with the release of energy:

• heat;
• ATP molecules are the main source of energy for any biochemical reaction.

Catabolism and anabolism are in constant balance, and directly depend on the following factors:

• Hormones, since these substances are the main regulators of catabolism and anabolism.
• The need to change the balance.
• Food.
• Metabolic rates.
• Amount of sleep.
• Other factors.

Let's look at a simple example of the processes of optimizing the body's resources. Initially, during the day, the body strives to break down energy and synthesize new cells.

At night, a reboot occurs, and it begins to kill unnecessary cells, breaking them down, and preparing for renewal.

In case of stress loads, catabolic processes are significantly accelerated. However, in this case, the acceleration of catabolism occurs in preparation for a powerful anabolic surge. All cells that are unable to withstand new levels of stress are killed and destroyed, replaced by more powerful and stronger ones.

Loads are precisely the factor that influences the shift in the balance between anabolic and catabolic processes.

When the stress in the body passes (for example, a person stops playing sports), the smart body optimizes resources so that it can survive in the event of a hunger strike or other powerful stress. And we all see muscle breakdown. This is especially noticeable if you follow athletes after their careers end. Usually they lose up to 40% of the accumulated muscle mass.

It is important to understand that physical activity is not the only factor that changes the balance between catabolism and anabolism. Any change in your daily routine or diet can move the slider in one direction or another.

© ogichobanov — depositphotos.com

How to increase anabolism

Only with a balance of anabolism and catabolism will proper metabolism and a healthy state of a person be ensured. Excessive predominance of one process over another causes the development of various pathologies, so you should consult a doctor before deciding to increase anabolism. You can make the energy exchange rate high in the following ways:

1. Diet. An increase in the amount of protein consumed leads to a natural increase in the volume of building materials for muscles. However, excess protein will not be as beneficial if you eat low-calorie foods, since the body will not have enough energy to absorb it. Nutrition must be balanced, then the cells will receive the necessary building material faster and muscle tissue will begin to grow.
2. Dream. Adequate rest is very important for anabolism, especially if a person was involved in sports that day.
3. Diet. Without the timely supply of nutrients to the body, the process of tissue growth is impossible.
4. Mental stability. To reduce the rate of catabolic reactions, it is important to avoid stressful situations.
5. Taking doping drugs. This measure is extremely undesirable for accelerating anabolism, since it often leads to problems at the hormonal level and other pathologies.

Components of metabolism

Metabolism is a set of any biochemical reactions aimed at growth, reproduction, treatment and many other necessary processes.

Enzymatic reactions, which are directly related to the transformation of useful substances, are divided into 2 different metabolic metabolisms: energy (catabolism) and plastic (anabolism). In a healthy and properly functioning body, the processes of catabolism and anabolism are strictly balanced, which allows for an even distribution of energy.

Anabolism and catabolism in sports

Since physical activity is a serious stress for the body, it triggers catabolic processes. Training creates the need to look for additional sources of energy (the body takes them not only from fat deposits, but also from proteins - the building blocks of muscles). What is muscle catabolism? This is a natural process in which the energy required for physical effort is produced through the breakdown of muscle tissue.

Anabolism and catabolism in sports is always a hot topic, since it is important for athletes to maintain maximum or even increase muscle volume. One of the main tasks of a person of any age who is actively involved in sports is to weaken the catabolic reactions of proteins and activate the anabolic process. A bodybuilder can balance anabolism and catabolism with proper nutrition, adherence to a rest regime and taking sports supplements (protein, etc.).

Plastic exchange

Energy and plastic metabolism use different methods of working with energy. Thus, plastic processes (also called anabolism and biosynthesis) use simple molecules to create more complex chemical compounds or end products.

Plastic exchange

They will be involved in maintaining growth, healing, reproduction or adaptation to environmental changes. At the cellular level, anabolic processes use simpler monomers to form polymers, resulting in the creation of complex molecular structures. For example, amino acids can be synthesized into protein elements.

Hormones that regulate plastic metabolism in the human body:

• Estrogen. Present in both men and women. Mainly produced in the ovaries and adrenal glands. Plays a big role in strengthening bone mass, regulates some female sexual characteristics and (breast and hip growth) improves the menstrual cycle.
• Testosterone. The main male sex hormone, which is also present in women. Produced from cholesterol cells in the ovaries and testes. Characterized by the regulation of male sexual characteristics (facial hair, rough voice), strengthens bones, helps build and maintain muscle mass. Testosterone levels can influence mood and the distribution of fat cells.
• Insulin. Produced in the pancreas by beta cells, which helps regulate the level of leukocytes. Without this hormone, the body will not be able to use glucose, the main source of energy. Impaired insulin production can lead to the development of diabetes.
• A growth hormone. Produced in the tissues of the pituitary gland. Stimulates and regulates growth in early and teenage years. Upon completion of maturation, it plays a large role in the natural restoration of bone mass.

In addition to its specific effects on humans, plastic metabolism also affects many other organisms. The main processes of anabolism include photosynthesis, chemosynthesis and biosynthesis - important elements for the existence of the entire biosphere of the Earth.

Photosynthesis

Photosynthesis is a particularly important process for the existence of all living organisms on Earth. It is characterized by the conversion of light energy into biochemical energy, which leads to further release in the form of complex molecular structures necessary for life.

The main product of photosynthesis is oxygen, which is converted from water and carbon dioxide molecules, which leads to the formation of glucose, along with which oxygen is released. The plastic process is only possible under direct exposure to light generated by solar energy.

Photosynthesis

Although photosynthesis is performed differently in each species, the process always begins with the absorption of light energy by protein reaction centers that contain the green pigments of chlorophyll. Such proteins are found within the chloroplast, most abundantly in leaf cells, whereas in bacteria they are embedded in the plasma membrane.

Some energy in light-dependent reactions is used to remove substances such as water, oxygen gas and others. The hydrogen released from water splitting is used to create two more compounds that serve as short-term energy storage, allowing it to be transferred to future biochemical processes.

Chemosynthesis

The process of chemosynthesis occurs in most microorganisms that are capable of simultaneously converting inorganic biological compounds into organic ones.

These include the following types of bacteria:

• sulfur bacteria;
• hydrogen;
• iron bacteria;
• nitrifying or aerobic.

Chemosynthesis energy is obtained through the oxidative reaction of inorganic compounds: potassium permanganate, iron, sulfur, ammonia and others. Oxidation occurs without the presence of oxygen molecules. The most significant element is carbon dioxide, with the help of which important organic compounds are synthesized.

Protein biosynthesis

Protein biosynthesis is a complex molecular process through which cells entering the body break down into separate parts, and then protein structures are synthesized. The transformation occurs in two stages: transcription and translation.

Protein biosynthesis

The first stage of transcription is characterized by copying genetic information from DNA to mRNA. Since bimolecular complementarity or correspondence between molecules and enzymes when reading from the entire code leads to degeneracy, data is used from only one genetic region.

As a result, amorphous-crystalline substances completely reproduce a small part of DNA with a difference in the equivalence of the uracil component to thymine. Translation differs from transcription by the transfer of synthesized code information to a protein polypeptide that is already under construction, the structure of which is indicated from the existing properties in the copied section.

The whole process takes place on non-membrane organelles, ribosomes, which are located in the cytoplasmic contents of the cell.

The information transfer stage is characterized by several stages:

1. Activation of amino acid compound with aminoacyl adenylate using adenosine triphosphates (ATP) and enzymatic molecules.
2. Release of adenosine triphosphoric acid, in which the amino acid binds to the transferred RNA.
3. The molecular complex formed and copied during the transcription stage combines with the non-membrane ribosome.
4. The necessary amino acid compounds are replaced in the peptide structure, which is characterized by the simultaneous release of the tRNA chain.

At the first stage of protein synthesis, 20 different proteinogenic amino acids can be activated at once. All of them are esterified with tRNA specific to them. This process occurs in the cytoplasm with the help of aminoacyl-tRNA synthetase. The release energy is provided by the consumption of adenosine triphosphates.

At the last stage of protein synthesis, the polypeptide chain ends with termination signals (three special stop codons) in the mRNA structure, which leads to its separation from the ribosome.

The release of polypeptide tRNA molecules is initiated by a specific protein factor that attaches to the ribosome and hydrolytically cleaves the ester bond between the polypeptide and the chain. All incoming biochemical substances are distributed throughout the living organism in such a way as to bring it as much benefit as possible.

Comparison of photosynthesis and respiration in eukaryotes

Energy and plastic metabolism are characterized by separate stages, which are completely different in functional impact. Thus, the main difference between photosynthesis and respiration is that the former occurs only in plants and some bacteria, while respiration occurs in all living organisms.

Other differences between eukaryotic respiration and photosynthesis are presented in the following table:

An important difference is the functional duration of each process. If photosynthesis occurs during the day only because it depends on light, then respiration is a continuous function, without which almost any living organism simply cannot exist.

Photosynthesis converts radiant or light energy into chemical or organic elements, including oxygen. Breathing releases biological potential energy for some other functions of the body.