Anabolic and catabolic processes in the human body. Anabolic and catabolic processes

The connection between catabolism and anabolism is manifested at three levels - carbon sources, energy and recovery reactions of anabolism.

At the level of carbon sources. Intermediate products of the central pathways of catabolism become substrates for anabolic reactions, during which the structural blocks necessary for the synthesis of macromolecules are formed.

At the energy level. The process of catabolism produces metabolic energy in the form of ATP; anabolic processes, as a rule, are endergonic and consume ATP.

At the level of recovery ability. Catabolic processes are mainly oxidative and serve as donors of high-energy electrons, while anabolism is characterized by the opposite. The main electron donor in the reduction reactions of biosynthesis is NADPH, the reduction of which occurs in catabolism reactions, mostly in the pentose phosphate pathway of glucose oxidation. Recall the essential difference in the functions of NADPH and NADH. During catabolism, reduced forms of both NADP + and NAD + are formed, and during anabolism, NADPH is consumed almost exclusively, while NADH serves as a donor of high-energy electrons in the processes of mitochondrial oxidation associated with ATP synthesis. The main difference in the reactions of catabolism and anabolism pathways is that they rarely repeat each other.

This is quite obvious when the catabolic product is not identical to the carbon source used in the anabolism process. Thus, during the synthesis of many amino acids, for example, during the breakdown of aromatic amino acids, acetyl-CoA and fumaric or succinic acids are formed, while for the synthesis of the same amino acids, phosphoenolpyruvic acid and aldotetrosophosphate serve as starting products.

The picture for the metabolism of fatty acids is different. Here, catabolism ends with the formation of acetyl-CoA, and biosynthesis begins with the same intermediate and follows a path that at first glance seems to be a simple repetition of the catabolic sequence of reactions in reverse order. Chapter 23 pointed out that this is far from the case. First, acetyl-CoA must first be converted to the more reactive malonyl-CoA, which is not a catabolic intermediate; secondly, the entire set of enzymes responsible for the conversion of malonyl-CoA to longer-chain acyl derivatives differs from the set of enzymes involved in catabolism, and, finally, thirdly, these enzymes are localized in a completely different cell compartment.

Even in glucose biosynthesis, which proceeds primarily by reversing a series of easily reversible enzymatic reactions of glycolysis, synthesis differs from degradation at the two most critical points of the entire successive reaction chain, namely at the beginning and end. So, for example, in the process of catabolism, glucose is converted into glucose-6-phosphate through a transphosphorylation reaction with the participation of ATP; however, during anabolism, it is formed from phosphate ester by simple hydrolysis. Pyruvate is formed catabolically from phosphoenolpyruvate by transphosphorylation - the transfer of a phosphate group to ADP; in anabolic processes, it is used in most organisms due to two related reactions: first, pyruvate is carboxylated to oxaloacetate and only then is it converted to phosphonolpyruvate.

It should be noted that the separation of biosynthesis and degradation pathways is important for effective regulation of metabolism.

Anabolism and catabolism are equally necessary processes in the body, and it is worth learning more about them in order not to believe the numerous myths.

When you sign up for a gym, you will often hear terms like anabolism, catabolism, and metabolism from a trainer.

The word “catabolism” can inspire fear, because this is muscle breakdown, as the instructor explained, and anabolism, on the contrary, is given odes and every trainee should certainly strive for it by closing the carbohydrate window, or mixing protein shakes right between sets.

But not everything is so simple. Both anabolism and catabolism are equally necessary processes in the body, so it’s worth learning more about them in order not to trust the numerous myths on this topic.

What is the relationship between anabolism, anabolics and the anabolic effect?

Anabolism is a biochemical process in the human body, due to which new compounds are created at the molecular level. In simple words- this is the generation of cells and the synthesis of proteins and hormones, due to which the growth of muscle fibers occurs, which all athletes achieve.

Anabolism occurs under the influence nutrients, minerals and vitamins that enter the body in sufficient quantities.

Several concepts in microbiology and medicine are associated with anabolism, one of them is the anabolic effect.

This is the explosive growth of cells in the body, due to a reaction to intense training, a change in diet, sports supplements or anabolics.

Anabolism can be not only in muscle tissue, but also in adipose tissue, in the broad sense of the word, this concept means the growth and renewal of any cells in the human body.

But if we talk about anabolism, as a process of increasing muscle fibers, then it depends on many factors:

1. Diet, sleep and rest.

2. The regularity of training and changing training programs.

3. Lack of stress and full recovery.

4. Body constitution and individual metabolism.

Metabolism or metabolism is directly related to the anabolic and catabolic processes that are its constituents. The metabolic rate differs in people of different physiques, lifestyles and ages.

Children have a very fast metabolism, which is why they love sweet foods that are full of fast carbohydrates, which are needed to get instant energy that a growing body wastes completely.

In people different type physique metabolic processes are different.

There are three body types:

Ectomorph

Mesomorph

Endomorph

Ectomorphs are naturally lean, have a fast metabolism, and require much more effort for muscle anabolism, as catabolic processes predominate in their body.

Mesomorphs are naturally athletic, their muscles respond easily to stress, anabolism and catabolism are in balance.

Endomorphs tend to be overweight, anabolism prevails over catabolism, they easily grow both muscle and adipose tissue.

Depending on the type of physique, you should select a training regimen and diet.

For example, endomorphs need to eat more protein foods and reduce fats and carbohydrates, while ectomorphs should not be afraid of fats and carbohydrates, because if they are not enough in the diet, the body will take energy from proteins, and muscle growth will be very slow.

Rest between workouts is important, because during a good rest, the body is completely restored, this is a time of active muscle growth, so do not neglect the days of rest from the gym.

Especially if you are not a professional sportsman. Yes, training athletes spend up to two workouts on the same day and on almost all days of the week, managing not only not to lose weight, but also to gain it.

They do this thanks to countless sports supplements that help you recover faster and train more efficiently, protein and a mega-calorie diet with big amount squirrel.

For an average amateur, 3-4 workouts per week on an ongoing basis are enough to see progress in the development of strength and endurance, changes in the body and an increase in muscle mass.

But, even if you practice regularly, you can come to the conclusion that you will stop noticing your own evolution in training.

Many during this period begin to take various drugs and buy sports nutrition.

But first of all, you need to pay attention to your training program, which is desirable to change or update every three months. It will not be superfluous to change the type of physical activity, for example, to do any new type of fitness.

The athlete's diet should be rich in protein foods. The more muscle mass you have, the more protein should be in the diet. Protein is needed to prevent the process of muscle breakdown, for their maintenance and growth.

How much protein you need can be calculated using special formulas that are easy to find on the Internet, but do not forget to adjust the average figures, focusing on the individual body constitution.

Sleep time is the time of recovery and renewal of all body functions at the cellular level.

For muscle anabolism, sleep is especially important, because during sleep, microtraumas of muscle fibers resulting from training are tightened, and, regenerating, muscles hypertrophy.

Should I be afraid of catabolism?

The process opposite to anabolic is catabolism. This is the breakdown of substances at the molecular level, the breakdown of complex compounds into simple ones.

Catabolic is the process of breaking down proteins, fats and carbohydrates obtained from food so that the body can function normally.

Thanks to one process, another occurs, the processes of anabolism and catabolism are interconnected and together they represent the metabolism (metabolism) in the body.

Without one process, the second is impossible, so it is foolish to be afraid of catabolism and believe the myths about it.

But if we apply the terms empirically, it is clear that athletes are not afraid of catabolism in general, but of losing muscle mass, which is not so easy to gain, especially for ectomorphs.

How to prevent muscle catabolism:

1. Train regularly and periodically change the training program.

2. Sleep 8-9 hours a day, rest regularly, distracted from worries and problems.

3. Avoid stress and shocks, relax.

4. Eat well, eat plenty of protein or supplement it with protein.

A good, fast metabolism is a sign healthy person. If you have any problems with the body, ailments or diseases, it is better to undergo a medical examination before visiting the hall.

The rate of its main processes depends on the level of metabolism, which means the time and effort to build muscles.

Now you know the meaning of anabolism and catabolism in the process of building your own body, which means you will be able to competently apply the knowledge gained in practice in order to train as efficiently as possible and get regular and full-fledged anabolism.

And metabolism is the basis of all life processes of the body:

• the transformation of energy and substances in a living organism, which allows cells to grow, develop and maintain their structure;
• exchange of energy and substances between the organism itself and environment.

The following factors influence the rate of metabolic reactions:

• floor: the main metabolic processes in men are 10-20% higher than in women;
• age: from 25 to 30 years old, the rate of metabolic processes decreases by an average of 3%, this happens every ten years;
• weight: the higher the total mass of internal organs, muscles and bones, the higher will be catabolism;
regular exercise speeds up metabolism - in the first two to three hours by an average of 30%, then during the day - by 5%.

Processes of anabolism and catabolism

Anabolism(plastic exchange) is the process of creating new cells and their structures, organic matter and tissues of the body, accompanied by the absorption of energy.

This process contributes to:

• development and growth of new tissues, including muscles;
• renewal and restoration of biological structures (cells, tissues);
• bone mineralization.

Anabolism processes occur at rest and under the influence of anabolic hormones (insulin, growth hormone, steroids), as well as substances with anabolic activity (amino acids, proteins, etc.).

Clinical examples of anabolism are the growth of nails, muscle mass, and the healing of bone fractures.

catabolism(energy metabolism) is the opposite of anabolism, the process of splitting complex substances, cell structures, organs and tissues into simple substances.

The stages of catabolism occur with the formation of energy in the form of ATP. Thus, the most important function of catabolism is to provide the body with the necessary energy from food and the further use of this energy for the needs of the body.

Catabolism is provoked by:

• starvation and other situations accompanied by an increase in the concentration of adrenaline;

Stages of catabolism

1. Large molecules (proteins, fats and carbohydrates) are broken down into simple molecules. This process takes place in gastrointestinal tract, outside the cell.
2. In the second stage, simple molecules enter the cell, the formation of energy begins.
3. The third stage is respiration (with the participation of oxygen), it ends with the formation of carbon dioxide, water and a large number energy.

A clinical example of catabolism is fat burning - weight loss.

The processes of anabolism and catabolism in the body can be in two states: equilibrium or temporary dominance over each other.

The predominance of the anabolic process contributes to the accumulation of mass and tissue growth, and the catabolic process to the destruction of tissue structures and the formation of energy.

The ratio of equilibrium or disequilibrium of anabolism and catabolism depends on age:

• In children, anabolic processes predominate;
• In adults, both processes are in balance, but their ratio may vary depending on the state of health, physical and psycho-emotional stress;
• In the elderly, the process of catabolism predominates.

Relationship between anabolism and catabolism

Anabolism and catabolism are two completely opposite processes, but despite this, they are closely interconnected.

As a result of catabolic reactions, substances and energy are formed, which are used in the anabolic process. And anabolism provides the supply of enzymes and substances necessary for catabolism.

For example, the human body can cover its need for 14 amino acids. The imbalance of these processes can lead to the death of the organism.

Let's see how it differs from other supplements.

Learn. It's not as difficult as it seems.

What to do to get rid of beer belly? To get started, read this: . All about nutrition and exercise.

Anabolism and catabolism in sports

Physical activity - training - is a strong stress for the body. And as we wrote above, this is what is needed to start the catabolic reaction. Training forces the body to look for energy not only in fats, which we are trying hard to burn, but also in proteins.

The result of such a catabolic reaction is not only weight loss, but also the loss of muscle mass as a result of muscle catabolism, which is terrible for the athlete.

Therefore, in sports great importance has protein catabolism, in which muscle protein is broken down into amino acids. The main task of an athlete is to weaken protein catabolism and start anabolism. On this principle, the nutrition of bodybuilders, athletes, complexes of sports supplements, and rest regimen are built.

Ways to change metabolism towards the predominance of anabolic processes:

Diet- Increase protein intake. The more protein, the more building material for cells and muscles. It is worth noting that the protein will not be so useful if the food is low in calories, because. the body will not have enough energy. Everything must be balanced.

You can use amino acid supplements in your diet, they are digested faster than protein products, tk. no time is wasted digesting them. As a result, muscle cells receive building material faster and, accordingly, recover faster and increase in volume.

Suppress catabolism- a difficult task, but doable: know the measure in training (you can even reduce them to 30 minutes), sleep a lot, do not skip meals, avoid stress and overwork.

Accelerate anabolism with doping- a special set of hormones, which is not recommended, because. it is prohibited and harmful to the body (leads to hormonal imbalance).

The dynamic balance of anabolism with catabolism ensures the correct metabolism and good health. Be healthy!

Anabolism and catabolism are the main metabolic processes.

Catabolism is the enzymatic breakdown of complex organic compounds, which is carried out inside the cell due to oxidation reactions. Catabolism is accompanied by the release of energy and its storage in high-energy phosphate bonds of ATP.

Anabolism is the synthesis of complex organic compounds - proteins, nucleic acids, polysaccharides - from simple precursors that enter the cell from the environment or are formed in the process of catabolism. Synthesis processes are associated with the consumption of free energy, which is supplied by ATP (Fig. 31).

Rice. 31 Scheme of metabolic pathways in a bacterial cell

Depending on the biochemistry of the process of dissimilation (catabolism), respiration and fermentation are distinguished.

Breath is a complex process of biological oxidation of various compounds), associated with the formation of a large amount of energy accumulated in the form of macroergic bonds in the structure of ATP (adenosine triphosphate), UTP (uridine triphosphate), etc., and the formation of carbon dioxide and water. Distinguish between aerobic and anaerobic respiration.

Fermentation- incomplete decomposition of organic compounds with the formation of a small amount of energy and energy-rich products.

Anabolism includes the processes of synthesis, which use the energy generated in the process of catabolism. In a living cell, the processes of catabolism and anabolism simultaneously and continuously proceed. Many reactions and intermediates are common to them.

Living organisms are classified according to what source of energy or carbon they use. Carbon is the main element of living matter. It plays a leading role in constructive metabolism.

Depending on the source of cellular carbon, all organisms, including prokaryotes, are divided into autotrophs and heterotrophs.

Autotrophs use CO 2 as the only source of carbon, reducing it with hydrogen, which is split off from water or another substance. They synthesize organic substances from simple inorganic compounds in the process of photo- or chemosynthesis.

Heterotrophs get carbon from organic compounds.

Living organisms can use light or chemical energy. Organisms that live off the energy of light are called phototrophic. They synthesize organic substances by absorbing the electromagnetic radiation of the Sun (light). These include plants, blue-green algae, green and purple sulfur bacteria.

Organisms that receive energy from substrates, food sources (oxidation energy of inorganic substances) are called chemotrophs. TO chemoheterotrophs include most bacteria, as well as fungi and animals.

There is a small group chemoautotrophs. Such chemosynthetic microorganisms include nitrifying bacteria, which, by oxidizing ammonia to nitrous acid, release the energy necessary for synthesis. Chemosynthetics also include hydrogen bacteria that obtain energy in the process of oxidizing molecular hydrogen.

Carbohydrates as a source of energy

In most organisms, the breakdown of organic substances occurs in the presence of oxygen - aerobic metabolism. As a result of this exchange, energy-poor end products (CO 2 and H 2 O) remain, but a lot of energy is released. The process of aerobic metabolism is called respiration, anaerobic - fermentation.

Carbohydrates are the main energy material that cells use primarily for chemical energy. In addition, proteins and fats can also be used during respiration, and alcohols and organic acids can also be used during fermentation.

Organisms break down carbohydrates in different ways, in which the most important intermediate product is pyruvic acid (pyruvate). Pyruvate is central to metabolism during respiration and fermentation. There are three main mechanisms for the formation of PVCs.

1. Fructose diphosphate (glycolysis) or Embden-Meyerhof-Parnas pathway is the universal path.

The process begins with phosphorylation (Fig. 32). With the participation of the enzyme hexokinase and ATP, glucose is phosphorylated at the sixth carbon atom with the formation of glucose-6-phosphate. It is the active form of glucose. It serves as the starting product for the breakdown of carbohydrates in any of three ways.

During glycolysis, glucose-6-phosphate isomerizes to fructose-6-phosphate, and then, under the action of 6-phosphofructokinase, it is phosphorylated at the first carbon atom. The resulting fructose-1,6-diphosphate under the action of the enzyme aldolase easily breaks down into two trioses: phosphoglyceraldehyde and dihydroxyacetone phosphate. Further conversion of C 3 -carbohydrates is carried out due to the transfer of hydrogen and phosphorus residues through a number of organic acids with the participation of specific dehydrogenases. All reactions of this pathway, with the exception of three involving hexokinase, 6-phosphofructokinase, and pyruvate kinase, are completely reversible. At the stage of formation of pyruvic acid, the anaerobic phase of carbohydrate conversion ends.

The maximum amount of energy received by a cell during the oxidation of one molecule of carbohydrates by the glycolytic pathway is 2 10 5 J.

Fig.32. Fructose diphosphate pathway for glucose breakdown

2. Pentose phosphate (Warburg-Dickens-Horecker)way also characteristic of most organisms more for plants, and for microorganisms plays an auxiliary role). Unlike glycolysis, the PF pathway does not form pyruvate.

Glucose-6-phosphate is converted to 6-phosphoglucolactone, which is decarboxylated (Fig. 33). In this case, ribulose-5-phosphate is formed, on which the oxidation process is completed. Subsequent reactions are considered as processes of conversion of pentose phosphates to hexose phosphates and vice versa, i.e. a cycle is formed. It is believed that the pentose phosphate pathway at one of the stages passes into glycolysis.

When passing through the PF path of every six molecules of glucose, one molecule of glucose-6-phosphate is completely oxidized to CO 2 and 6 molecules of NADP + are reduced to NADP·H 2. As a mechanism for obtaining energy, this pathway is two times less efficient than the glycolytic one: 1 molecule of ATP is formed for each glucose molecule.

Rice. 33. Pentose phosphate cleavage pathway of glucose-6-phosphate

The main purpose of this pathway is to supply the pentoses necessary for the synthesis of nucleic acids, and to ensure the formation of most of the NADP H 2 necessary for the synthesis of fatty acids, steroids.

3. Entner-Doudoroff pathway (ketodeoxyphosphogluconate or KDPG pathway) found only in bacteria. Glucose is phosphorylated by the ATP molecule with the participation of the hexokinase enzyme (Fig. 34).

Fig.34. The Entner-Doudor pathway of glucose breakdown

The product of phosphorylation, glucose-6-phosphate, is dehydrated to 6-phosphogluconate. Under the action of the enzyme phosphogluconate dehydrogenase, water is split off from it and 2-keto-3-deoxy-6-phosphogluconate (KDPG) is formed. The latter is cleaved by a specific aldolase into pyruvate and glyceraldehyde-3-phosphate. Glyceraldehyde is further exposed to the enzymes of the glycolytic pathway and transformed into a second pyruvate molecule. In addition, this pathway supplies the cell with 1 ATP molecule and 2 NAD·H 2 molecules.

Thus, the main intermediate product of the oxidative breakdown of carbohydrates is pyruvic acid, which, with the participation of enzymes, is converted into various substances. PVC formed by one of the pathways in the cell undergoes further oxidation. The released carbon and hydrogen are removed from the cell. Carbon is released in the form of CO 2 , hydrogen is transferred to various acceptors. Moreover, either a hydrogen ion or an electron can be transferred, so the transfer of hydrogen is equivalent to the transfer of an electron. Aerobic respiration, anaerobic respiration, and fermentation are distinguished depending on the final hydrogen acceptor (electron).

Breath

Respiration is a redox process that goes with the formation of ATP; Organic or inorganic compounds play the role of hydrogen (electron) donors in it, while inorganic compounds serve as hydrogen (electron) acceptors in most cases.

If the final electron acceptor is molecular oxygen, the respiratory process is called aerobic respiration. In some microorganisms, compounds such as nitrates, sulfates, and carbonates serve as the final electron acceptor. This process is called anaerobic respiration.

Aerobic respiration- the process of complete oxidation of substrates to CO 2 and H 2 O with the formation of a large amount of energy in the form of ATP.

Complete oxidation of pyruvic acid occurs under aerobic conditions in the tricarboxylic acid cycle (CTC or Krebs cycle) and the respiratory chain.

Aerobic respiration consists of two phases:

one). The pyruvate formed during glycolysis is oxidized to acetyl-CoA, and then to CO 2, and the released hydrogen atoms move to acceptors. This is how the CTC works.

2). Hydrogen atoms cleaved off by dehydrogenases are accepted by the coenzymes of anaerobic and aerobic dehydrogenases. Then they are carried along the respiratory chain, in some parts of which a significant amount of free energy is formed in the form of high-energy phosphates.

Tricarboxylic acid cycle (Krebs cycle, CTC)

Pyruvate formed during glycolysis, with the participation of the multienzyme complex of pyruvate dehydrogenase, is decarboxylated to acetaldehyde. Acetaldehyde, combining with the coenzyme of one of the oxidative enzymes - coenzyme A (CoA-SH), forms "activated acetic acid" - acetyl-CoA - a high-energy compound.

Acetyl-CoA, under the action of citrate synthetase, reacts with oxaloacetic acid (oxaloacetate), forming citric acid (citrate C 6), which is the main link in the TCA cycle (Fig. 35). Citrate after isomerization turns into isocitrate. This is followed by oxidative (cleavage of H) decarboxylation (cleavage of CO 2) of isocitrate, the product of which is 2-oxoglutarate (C 5). Under the influence of the enzyme complex of α-ketoglutarate dehydrogenase with the active group of NAD, it is converted into succinate, losing CO 2 and two hydrogen atoms. The succinate is then oxidized to fumarate (C4) and the latter is hydrated (addition of H2O) to malate. In the final reaction of the Krebs cycle, malate is oxidized, which leads to the regeneration of oxaloacetate (C 4). Oxaloacetate reacts with acetyl-CoA and the cycle repeats again. Each of the 10 TCA reactions, with the exception of one, is easily reversible. Two carbon atoms enter the cycle in the form of acetyl-CoA and the same number of carbon atoms leave this cycle in the form of CO 2 .

Rice. 35. Krebs cycle (according to V.L. Kretovich):

1, 6 – system of oxidative decarboxylation; 2 - citrate synthetase, coenzyme A; 3, 4 - aconite hydratase; 5 - isocitrate dehydrogenase; 7 - succinate dehydrogenase; 8 - fumarate hydratase; 9 - malate dehydrogenase; 10 - spontaneous transformation; 11 - pyruvate carboxylase

As a result of four redox reactions of the Krebs cycle, three pairs of electrons are transferred to NAD and one pair of electrons to FAD. The electron carriers NAD and FAD restored in this way are then oxidized already in the electron transport chain. The cycle produces one ATP molecule, 2 CO 2 molecules and 8 hydrogen atoms.

The biological significance of the Krebs cycle is that it is a powerful supplier of energy and "building blocks" for biosynthetic processes. The Krebs cycle operates only under aerobic conditions; under anaerobic conditions, it is open at the level of α-ketoglutarate dehydrogenase.

respiratory chain

The last step in catabolism is oxidative phosphorylation. During this process, most of the metabolic energy is released.

The electron carriers NAD and FAD reduced in the Krebs cycle undergo oxidation in the respiratory or electron transport chain. Carrier molecules are dehydrogenases, quinones and cytochromes.

Both enzyme systems in prokaryotes are located in the plasma membrane, and in eukaryotes - in the inner membrane of mitochondria. Electrons from hydrogen atoms (NAD, FAD) pass through a complex chain of carriers to molecular oxygen, reducing it, and water is formed.

Balance. Calculations of the energy balance showed that during the breakdown of glucose by the glycolytic pathway and through the Krebs cycle, followed by oxidation in the respiratory chain to CO 2 and H 2 O, 38 ATP molecules are formed for each glucose molecule. Moreover, the maximum amount of ATP is formed in the respiratory chain - 34 molecules, 2 molecules - in the EMT pathway and 2 molecules - in the TCA (Fig. 36).

Incomplete oxidation of organic compounds

Respiration is usually associated with the complete oxidation of the organic substrate, i.e. the end products of decomposition are CO 2 and H 2 O.

However, some bacteria and a number of fungi do not completely oxidize carbohydrates. The end products of incomplete oxidation are organic acids: acetic, citric, fumaric, gluconic, etc., which accumulate in the medium. This oxidative process is used by microorganisms to obtain energy. However, the total energy yield in this case is much lower than with complete oxidation. Part of the energy of the initial substrate being oxidized is stored in the resulting organic acids.

Microorganisms that develop due to the energy of incomplete oxidation are used in the microbiological industry to obtain organic acids and amino acids.

Our body is an amazing system capable of maintaining stable connections with the environment. This is done through metabolism or, as it is also called, metabolism. The very same metabolism is divided into two components: catabolism and anabolism Many people confuse these concepts. But they are fundamentally different. Let's understand what catabolism is.

Differences between catabolism and anabolism

These processes are opposite in nature. Anabolism is the process of synthesizing more complex substances from simpler ones. What is catabolism? This is the reverse process. An example of anabolism is a set of muscle mass. And as an example for catabolism, a number of important reactions for the human body can be cited.

For example, many people love potatoes, right? One of the main substances in it, creating a pleasant taste, is starch. This substance is a polysaccharide. This means that it is a very complex carbohydrate in nature. Accordingly, it consists of many other carbohydrates, and it can be decomposed into less complex substances. At the very end, starch is decomposed by the body to and there is catabolism.

Alcohol catabolism

The second example of catabolism is the decomposition of alcohol to acetic acid. This process is carried out in two steps using two enzymes. The first is alcohol dehydrogenase. This enzyme is responsible for the catabolism of ethanol to acetaldehyde. This substance is toxic, so it cannot stay in the body for a long time. That is what causes the hangover. But that's not the point.

The second step in the catabolism of ethyl alcohol is the breakdown of acetaldehyde by the enzyme acetaldehyde dehydrogenase to acetic acid, which is excreted from the body. There are a number of other examples of catabolism. For example, fats can be broken down into glycerol and fatty acids, while proteins can be broken down into amino acids. For bodybuilders, the latter type of catabolism is quite unpleasant, since it does not allow you to gain muscle mass.

Science catabolism

Catabolism is designed so that the body can receive energy. In fact, any substances that are processed by our body are a source of ATP - adenosine triphosphate. These are special molecules designed for accumulation, that is, the accumulation of energy in the body. The amount of this substance is quite limited. Therefore, it needs to be constantly replenished. And this can only be done in one way - with the help of catabolism. The process takes place in several stages. Let us consider in more detail all the stages of catabolism.

First step

The first stage of catabolism is the breakdown of substances obtained from food with the help of special enzymes. For some substances, hormones can act as an enzyme. For example, sugar breaks down insulin produced by the pancreas. At the same time, only the release of heat is typical for this stage. It doesn't disappear without a trace.

In particular, it is used to maintain normal level the vital activity of the organism. And we feel this process as the preservation of a certain body temperature. However, this circle is quite interesting. After all, catabolism can be carried out only in the presence of a certain temperature. Heat is a natural catalyst for any chemical processes in the body or in the external environment. The process of splitting vital substances is quite complex, so the second stage is indispensable.

Second phase

The second step is called glycolysis. At this stage, glucose is broken down. This process takes place in the cytoplasm of the cell. As a consequence of the second stage, 40% is stored as ATP, and the rest of the resulting energy is used as heat. In general, thermoregulation in our body, as we see, is very expensive for it. Much more than half of all the energy received is spent precisely on maintaining normal body temperature. This stage occurs without the participation of oxygen.

The third stage - oxygen

This stage of catabolism occurs with the direct participation of oxygen. It is carried out in mitochondria, which are our natural batteries. These elements of our body are very small, they cannot be seen with the naked eye. At the same time, these batteries are present in every cell capable of metabolism. And it is in them that ATP is accumulated. And the third stage is completely tied to the synthesis

The total path of catabolism can be called a set of such processes:

• Oxidation of pyruvate to acetyl-CoA. This process occurs under the influence of enzymes that form a combination under an interesting name. But these are already details that are not particularly important to an ordinary person.
• Next comes the oxidation of acetyl-Coa. This is due to the so-called tricarboxylic acid cycle. It is also called the Krebs cycle. This process is key, intended for Not all, of course, but only those who use oxygen. It is thanks to the further formation of ATP in the process of anabolism (synthesis), which is the main source of energy in the cell.
• After that, energy is released, it is accumulated (accumulation). This is due to the dehydrogenation of metabolites, which were obtained during the previous two processes of catabolism. Dehydrogenation itself occurs in the mitochondrial electron transport chains.

These processes of catabolism are very important for humans. Without them, it would be impossible to exist, since during the catabolism of ATP, energy is released, which is later used as a universal remedy absorbed by our organs.

Yes, proteins are broken down in our body into amino acids. But not only this happens in our body. Among other things, amino acids are also direct participants in catabolism. The process itself is very complex, so only the basic information will be given, which will not be difficult enough for readers. Amino acids are the main building blocks of proteins.

There is not a single part of the body that does not need proteins. However, some of them can be harmful. Diseases that occur due to the appearance of abnormal proteins in the body are called prion diseases. And, interestingly, they can be infected in one moment.

conclusions

We figured out what catabolism is and why our body needs it. The reason is very simple. Even the most necessary substances in our body sometimes turn out to be superfluous. However, we cannot do without these substances. Catabolism allows not only to get energy, but also to eliminate the excess of what our body needs. It's just that too much of it is also bad. And this fact must be taken into account.

It is important to understand what catabolism is not only for general education, but also, for example, for burning excess weight. But at the same time, you need to be extremely careful, since catabolism can burn muscle mass in addition to fat. He doesn't care what hits the target.