What is an enzyme in biology. How to detect violations in the synthesis of digestive enzymes? Interesting facts you didn't know

The date: 22.09.2019

Various chemical processes are the basis of the life of any organism. the main role they are reserved for enzymes. Enzymes or enzymes are natural biocatalysts. In the human body, they take an active part in the process of digestion of food, the functioning of the central nervous system and stimulation of new cell growth. By their nature, enzymes are proteins designed to speed up various biochemical reactions in the body. The breakdown of proteins, fats, carbohydrates and minerals are processes in which enzymes are one of the main active components.

There are quite a few varieties of enzymes, each of which is designed to act on a particular substance. Protein molecules are unique and cannot replace each other. Their activity requires a certain temperature range. Ideal for human enzymes normal temperature body. Oxygen and sunlight destroy enzymes.

General characteristics of enzymes

Being organic substances of protein origin, enzymes act on the principle of inorganic catalysts, accelerating reactions in the cells in which they are synthesized. A synonym for the name of such protein molecules is enzymes. Almost all reactions in cells occur with the participation of specific enzymes. They are divided into two parts. The first is directly the protein part, represented by a protein of the tertiary structure and called the apoenzyme, the second is the active center of the enzyme, called the coenzyme. The latter can be organic / inorganic substances, and it is he who acts as the main "accelerator" of biochemical reactions in the cell. Both parts form a single protein molecule called a holoenzyme.

Each enzyme is designed to act on a specific substance, called a substrate. The result of the reaction that has taken place is called the product. The names of the enzymes themselves are quite often formed on the basis of the name of the substrate with the addition of the ending "-aza". For example, an enzyme designed to break down succinic acid (succinate) is called succinate dehydrogenase. In addition, the name of the protein molecule is determined by the type of reaction, the implementation of which it provides. Thus, dehydrogenases are responsible for the process of regeneration and oxidation, and hydrolases are responsible for the cleavage of chemical bonds.

The action of enzymes of various types is directed to certain substrates. That is, the participation of protein molecules in certain biochemical reactions is individual. Each enzyme is associated with its substrate and can only work with it. The apoenzyme is responsible for the continuity of this connection.

Enzymes can be in a free state in the cytoplasm of the cell or interact with more complex structures. There are also certain types of them that act outside the cell. These include, for example, enzymes that break down proteins and starch. In addition, enzymes can be produced by various microorganisms.

To study enzymes and the processes occurring with their participation, a separate area of biochemical science is intended - enzymology. For the first time, information about special protein molecules acting on the principle of catalysts appeared as a result of studying the digestive processes and fermentation reactions that occur in the human body. A significant contribution to the development of modern enzymology is attributed to L. Pasteur, who believed that all biochemical reactions in the body occur with the participation of exclusively living cells. The inanimate "participants" of such reactions were first announced by E. Buchner at the beginning of the 20th century. At that time, the researcher was able to determine that a cell-free yeast extract acts as a catalyst in the process of fermenting sucrose, followed by the release of ethyl alcohol and carbon dioxide. This discovery was a decisive impetus for a detailed study of the so-called catalysts for various biochemical processes in the body.

Already in 1926, the first enzyme, urease, was isolated. The author of the discovery was J. Sumner, an employee of Cornell University. After that, within one decade, scientists isolated a number of other enzymes, and the protein nature of all organic catalysts was finally proven. To date, the world knows more than 700 different enzymes. But at the same time, modern enzymology continues to actively study, isolate and study the properties of certain types of protein molecules.

Enzymes: protein nature

As well as, enzymes are usually divided into simple and complex. The former are compounds composed of amino acids, such as trypsin, pepsin or lysozyme. Complex enzymes, as mentioned above, consist of a protein part with amino acids (apoenzyme) and a non-protein part, called a cofactor. Only complex enzymes can participate in bioreactions. In addition, like proteins, enzymes are mono- and polymers, that is, they consist of one or more subunits.

The general properties of enzymes as protein structures are:

efficiency of action, implying a significant acceleration of chemical reactions in the body;
selectivity to the substrate and the type of reaction performed;
sensitivity to temperature, acid-base balance and other non-specific physico-chemical factors of the environment in which enzymes operate;
sensitivity to the action of chemical reagents, etc.

The main role of enzymes in the human body is the transformation of some substances into others, that is, substrates into products. They act as catalysts in more than 4 thousand biochemical vital reactions. The functions of enzymes are to direct and regulate metabolic processes. As inorganic catalysts, enzymes can greatly accelerate the forward and reverse bioreaction. It is worth noting that during their action the chemical equilibrium is not disturbed. The reactions that take place ensure the breakdown and oxidation of nutrients that enter the cells. Each protein molecule can perform a huge number of actions per minute. At the same time, the protein of enzymes, reacting with various substances, remains unchanged. The energy generated during the oxidation of nutrients is used by the cell in the same way as the breakdown products of substances necessary for the synthesis of organic compounds.

Today, not only enzyme preparations have found wide application medical purpose. Enzymes are also used in food and textile industry, in modern pharmacology.

Enzyme classification

At the meeting of the V International Biochemical Union, held in Moscow in 1961, the modern classification of enzymes was adopted. This classification implies their division into classes, depending on the type of reaction in which the enzyme acts as a catalyst. In addition, each class of enzymes is divided into subclasses. To designate them, a code of four numbers separated by dots is used:

the first number indicates the reaction mechanism in which the enzyme acts as a catalyst;
the second number indicates the subclass to which the enzyme belongs;
the third number is a subclass of the described enzyme;
and the fourth is the serial number of the enzyme in the subclass to which it belongs.

In total, six classes of enzymes are distinguished in the modern classification of enzymes, namely:

Oxidoreductases are enzymes that act as catalysts in various redox reactions that occur in cells. This class includes 22 subclasses.
Transferases are a class of enzymes with 9 subclasses. It includes enzymes that provide transport reactions between different substrates, enzymes that take part in the reactions of the interconversion of substances, as well as the neutralization of various organic compounds.
Hydrolases are enzymes that break the intramolecular bonds of a substrate by attaching water molecules to it. This class has 13 subclasses.
Lyases are a class that contains only complex enzymes. It has seven subclasses. Enzymes belonging to this class act as catalysts in the reactions of breaking C-O, C-C, C-N and other types of organic bonds. Also, enzymes of the lyase class are involved in reversible biochemical cleavage reactions in a non-hydrolytic way.
Isomerases are enzymes that act as catalysts in the chemical processes of isomeric transformations occurring in one molecule. As in the previous class, they include only complex enzymes.
Ligases, otherwise known as synthetases, are a class that includes six subclasses and represents enzymes that catalyze the process of joining two molecules under the influence of ATP.

The composition of enzymes combines separate areas responsible for the performance of specific functions. So, in the composition of enzymes, as a rule, active and allosteric centers are isolated. The latter, by the way, is not found in all protein molecules. The active site is a combination of amino acid residues responsible for contact with the substrate and catalysis. The active center, in turn, is divided into two parts: anchor and catalytic. Enzymes consisting of several monomers may contain more than one active site.

The allosteric center is responsible for the activity of enzymes. This part of enzymes got its name due to the fact that its spatial configuration has nothing to do with the substrate molecule. The change in the rate of the reaction that occurs with the participation of the enzyme is determined by the binding of various molecules to the allosteric center. Enzymes containing allosteric centers in their composition are polymeric proteins.

The mechanism of action of enzymes

The action of enzymes can be divided into several stages, in particular:

the first stage involves the attachment of the substrate to the enzyme, as a result of which the enzyme-substrate complex is formed;
the second stage consists in converting the resulting complex into one or several transitional complexes at once;
the third stage is the formation of the enzyme-product complex;
and, finally, the fourth stage involves the separation of the final product of the reaction and the enzyme, which remains unchanged.

In addition, the action of enzymes can occur with the participation of various mechanisms of catalysis. Thus, acid-base and covalent catalysis are isolated. In the first case, enzymes that contain specific amino acid residues in their active center participate in the reaction. Such groups of enzymes are excellent catalysts for numerous reactions in the body. Covalent catalysis involves the action of enzymes that form unstable complexes upon contact with substrates. The result of such reactions is the formation of products through intramolecular rearrangements.

There are also three main types of enzymatic reactions:

"Ping-pong" is a reaction in which an enzyme combines with one substrate, borrowing certain substances from it, and then interacts with another substrate, giving it the resulting chemical groups.
Sequential reactions imply successive addition of one and then another substrate to the enzyme, as a result of which the so-called “triple complex” is formed, in which catalysis occurs.
Random interactions are reactions in which substrates interact with an enzyme randomly, and after catalysis, they are split off in the same order.

The activity of enzymes is unstable and largely depends on various environmental factors in which they have to act. So the main indicators for the activity of enzymes are the factors of internal and external influence on a cell. The activity of enzymes is changed in catales, showing the amount of enzyme that converts per second 1 mol of the substrate with which it interacts. The international unit of measure is E, showing the amount of enzyme capable of converting 1 µmol of substrate in 1 minute.

Enzyme Inhibition: Process

One of the main directions in modern medicine and enzymology in particular is the development of methods for controlling the rate of metabolic reactions that occur with the participation of enzymes. Inhibition is commonly referred to as a decrease in enzyme activity through the use of various compounds. Accordingly, a substance that provides a specific decrease in the activity of protein molecules is called an inhibitor. Exist different kinds inhibition. So, depending on the binding strength of the enzyme with the inhibitor, the process of their interaction can be reversible and, accordingly, irreversible. And depending on how the inhibitor acts on the active site of the enzyme, the process of inhibition can be competitive or non-competitive.

Enzyme activation in the body

Unlike inhibition, the activation of enzymes implies an increase in their action in the ongoing reactions. Substances that allow you to get the desired result are called activators. Such substances may be organic or inorganic in nature. For example, bile acids, glutathione, enterokinase, vitamin C, various tissue enzymes, etc. can act as organic activators. Pepsinogen and ions of various metals, most often divalent, can be used as inorganic activators.

Various enzymes, the reactions that occur with their participation, as well as their result, have found their wide application in diverse fields. For many years, the action of enzymes has been actively used in the food, leather, textile, pharmaceutical and many other industries. For example, with the help of natural enzymes, researchers are trying to increase the efficiency of alcoholic fermentation in the manufacture of alcoholic beverages, improve food quality, develop new weight loss methods, etc. But it is worth noting that the use of enzymes in various industries in comparison with the use of chemical catalysts loses significantly. After all, the main difficulty in implementing such a task in practice is the thermal instability of enzymes and their increased sensitivity to the effects of various factors. It is also impossible to reuse enzymes in production due to the difficulty of separating them from the finished products of the reactions performed.

In addition, the action of enzymes has found its active use in medicine, the agricultural and chemical industries. Let us consider in more detail how and where the action of enzymes can be used:

Food industry. Everyone knows that a good dough should rise and swell when baking. But not everyone understands exactly how this happens. In the flour, from which the dough is made, there are many different enzymes. So, amylase in the composition of flour is involved in the process of decomposition of starch, in which carbon dioxide is actively released, contributing to the so-called "swelling" of the dough. The stickiness of the dough and the retention of CO2 in it is provided by the action of an enzyme called protease, which is also found in flour. It turns out that such, it would seem. simple things, like making dough for baking, involve complex chemical processes. Also, some enzymes, the reactions that occur with their participation, have gained special demand in the field of alcohol production. Various enzymes are used in yeast to ensure the quality of the alcohol fermentation process. In addition, some enzymes (such as papain or pepsin) help dissolve sediment in alcoholic beverages. Enzymes are also actively used in the production fermented milk products and cheese as well.

In the leather industry, enzymes are used to efficiently break down proteins, which is most important when removing stubborn stains from various food products, blood, etc.

Cellulase can be used in the production of laundry detergents. But when using such powders, in order to obtain the stated result, it is necessary to observe the permissible temperature regime of washing.

In addition, in production feed additives enzymes are used to increase their nutritional value, hydrolysis of proteins and non-starch polysaccharides. In the textile industry, enzymes make it possible to change the surface properties of textiles, and in the pulp and paper industry, to remove ink and toners during paper recycling.

The huge role of enzymes in the life of modern man is undeniable. Already today, their properties are actively used various areas, but there is also a continuous search for new applications for the unique properties and functions of enzymes.

Human enzymes and hereditary diseases

Many diseases develop against the background of enzymopathies - violations of the functions of enzymes. Allocate primary and secondary enzymopathies. Primary disorders are hereditary, secondary - acquired. Hereditary enzymopathies are usually classified as metabolic diseases. Inheritance of genetic defects or reduced enzyme activity occurs predominantly in an autosomal recessive manner. For example, a disease such as phenylketonuria is the result of a defect in an enzyme such as phenylalanine-4-monooxygenase. This enzyme is normally responsible for the conversion of phenylalanine to tyrosine. As a result of violations of the functions of the enzyme, the accumulation of abnormal metabolites of phenylalanine, which are toxic to the body, occurs.

Also referred to as enzymopathies, the development of which is caused by a violation of the metabolism of purine bases and, as a result, a stable increase in the level uric acid in blood. Galactosemia is another disease caused by a hereditary dysfunction of enzymes. Developing this pathology due to a violation of carbohydrate metabolism, in which the body cannot convert galactose into glucose. The consequence of such a violation is the accumulation of galactose and its metabolic products in cells, which leads to damage to the liver, central nervous system and other vital body systems. The main manifestations of galactosemia are diarrhea, vomiting, which appear immediately after the birth of a child, obstructive jaundice, cataracts, and delayed physical and intellectual development.

Various glycogenoses and lipidoses also belong to hereditary enzymopathies, otherwise referred to as enzymopathologies. The development of such disorders is due to low enzymatic activity in the human body or its complete absence. Hereditary metabolic defects, as a rule, are accompanied by the development of diseases with varying degrees of severity. At the same time, some enzymopathies can be asymptomatic and are determined only when appropriate diagnostic procedures are carried out. But mostly the first symptoms of hereditary metabolic disorders appear already in early childhood. This happens less often in older children and even more so in adults.

In the diagnosis of hereditary enzymopathies, an important role is played by the genealogical method of research. At the same time, experts check the reactions of enzymes laboratory way. Hereditary fermentopathy can lead to disorders in the production of hormones, which are of particular importance for the full functioning of the body. For example, the adrenal cortex produces glucocorticoids responsible for the regulation of carbohydrate metabolism, mineralocorticoids involved in water-salt metabolism, as well as androgenic hormones that directly affect the development of secondary sexual characteristics in adolescents. Thus, a violation of the production of these hormones can lead to the development of numerous pathologies from various organ systems.

The process of food processing in the human body occurs with the participation of various digestive enzymes. In the process of digestion of food, all substances are broken down into small molecules, because only low molecular weight compounds are able to penetrate the intestinal wall and be absorbed into the bloodstream. A special role in this process is given to enzymes that break down proteins to amino acids, to glycerol and fatty acids, and starch to sugars. The breakdown of proteins is provided by the action of the enzyme pepsin contained in the main organ. digestive system- stomach. Part of the digestive enzymes is produced in the intestines by the pancreas. In particular, these include:

trypsin and chymotrypsin, the main purpose of which is the hydrolysis of proteins;
amylase - enzymes that break down fats;
lipase - digestive enzymes that break down starch.

Digestive enzymes such as trypsin, pepsin, chymotrypsin are produced in the form of proenzymes, and only after they enter the stomach and intestines do they become active. This feature protects the tissues of the stomach and pancreas from their aggressive effects. In addition, the inner shell of these organs is additionally covered with a layer of mucus, which ensures their even greater safety.

Some digestive enzymes are also produced in the small intestine. For the processing of cellulose that enters the body along with plant foods, an enzyme with the consonant name of cellulase is responsible. In other words, in almost every department gastrointestinal tract digestive enzymes are produced, starting with the salivary glands and ending with the large intestine. Each type of enzyme performs its own functions, together providing high-quality digestion of food and full absorption of all useful substances in the body.

pancreatic enzymes

The pancreas is an organ of mixed secretion, that is, it performs both endo- and exogenous functions. The pancreas, as mentioned above, produces a number of enzymes that are activated under the influence of bile, which enters the digestive organs along with enzymes. Pancreatic enzymes are responsible for breaking down fats, proteins, and carbohydrates into simple molecules that can pass through the cell membrane into the bloodstream. Thus, thanks to the enzymes of the pancreas, there is a complete assimilation of useful substances that enter the body along with food. Let us consider in more detail the action of enzymes synthesized by the cells of this organ of the gastrointestinal tract:

amylase, together with small intestinal enzymes such as maltase, invertase and lactase, provide a process for the breakdown of complex carbohydrates;
proteases, otherwise called proteolytic enzymes in the human body, are represented by trypsin, carboxypeptidase and elastase and are responsible for the breakdown of proteins;
nucleases - pancreatic enzymes, represented by deoxyribonuclease and ribonuclease, acting on the amino acids of RNA, DNA;
lipase is a pancreatic enzyme responsible for converting fats into fatty acids.

The pancreas also synthesizes phospholipase, esterase and alkaline phosphatase.

The most dangerous in the active form are proteolytic enzymes produced by the body. If the process of their production and release to other organs of the digestive system is disturbed, enzymes are activated directly in the pancreas, which leads to the development acute pancreatitis and related complications. Inhibitors of proteolytic enzymes that can slow down their action are pancreatic polypeptide and glucagon, somatostatin, peptide YY, enkephalin and pancreastatin. These inhibitors can inhibit the production of pancreatic enzymes by affecting the active elements of the digestive system.

The main processes of digestion of food entering the body take place in the small intestine. In this section of the gastrointestinal tract, enzymes are also synthesized, the activation process of which occurs in conjunction with the enzymes of the pancreas and gallbladder. The small intestine is the part of the digestive tract where the final stages of hydrolysis of nutrients that enter the body along with food take place. It synthesizes various enzymes that break down oligo- and polymers into monomers, which can be absorbed by the mucosa without problems. small intestine and enter the lymph and bloodstream.

Under the influence of small intestine enzymes, the process of splitting proteins that have undergone preliminary transformation in the stomach into amino acids, complex carbohydrates into monosaccharides, fats into fatty acids and glycerol takes place. In the composition of intestinal juice, there are over 20 types of enzymes involved in the process of digestion of food. With the participation of pancreatic and intestinal enzymes, the complete development of chyme (partially digested food) is ensured. All processes in the small intestine occur within 4 hours after the chyme enters this section of the digestive tract.

An important role in the digestion of food in the small intestine is played by bile, which enters the duodenum during digestion. There are no enzymes in the bile itself, but this biological fluid enhances the action of enzymes. The most significant bile is for the breakdown of fats, turning them into an emulsion. Such emulsified fat is broken down much faster under the influence of enzymes. Fatty acids, interacting with bile acids, are converted into easily soluble compounds. In addition, the secretion of bile stimulates intestinal motility and the production of digestive juice by the pancreas.

Intestinal juice is synthesized by glands located in the mucosa of the small intestine. The composition of such a liquid contains digestive enzymes, as well as enterokinase, designed to activate the action of trypsin. In addition, intestinal juice contains an enzyme called erepsin, necessary for the final step in the breakdown of proteins, enzymes that act on various types of carbohydrates (for example, amylase and lactase), and lipase, designed to convert fats.

gastric enzymes

The process of digestion of food occurs in stages in each section of the gastrointestinal tract. So, it begins in the oral cavity, where food is crushed by teeth and mixed with saliva. Saliva contains enzymes that break down sugar and starch. After the oral cavity, the crushed food enters the esophagus into the stomach, where the next stage of its digestion begins. The main gastric enzyme is pepsin, designed to convert proteins into peptides. Also in the stomach there is gelatinase - an enzyme, the process of splitting collagen and gelatin, for which the main task is. Plus, food in the cavity of this organ is exposed to the action of amylase and lipase, respectively, which break down starch and fats.

From quality digestive process depends on the ability of the body to obtain all the necessary nutrients. The splitting of complex molecules into many simple ones ensures their further absorption into the blood and lymph flow at subsequent stages of digestion in other parts of the gastrointestinal tract. Insufficient production of gastric enzymes can cause the development of various diseases.

Liver enzymes are of great importance for the course of various biochemical processes in the body. The functions of the protein molecules produced by this organ are so numerous and diverse that all liver enzymes are usually divided into three main groups:

Secretory enzymes designed to regulate the process of blood clotting. These include cholinesterase and prothrombinase.
Liver indicator enzymes, including aspartate aminotransferase, abbreviated as AST, alanine aminotransferase, with the corresponding designation ALT, and lactate dehydrogenase, LDH. The listed enzymes signal damage to the tissues of the organ, in which hepatocytes are destroyed, "leave" the liver cells and enter the bloodstream;
Excretory enzymes are produced by the liver and leave the organ with bile sweat. These enzymes include alkaline phosphatase. With violations of the outflow of bile from the organ, the level of alkaline phosphatase increases.

Violation of the work of certain liver enzymes in the future can lead to the development of various diseases or signal their presence at the present time.

One of the most informative tests for liver diseases is blood biochemistry, which allows you to determine the level of indicator enzymes AST, ATL. So, the normal indicators of aspartate aminotransferase for a woman are 20-40 U / l, and for the stronger sex - 15-31 U / l. An increase in the activity of this enzyme may indicate damage to hepatocytes of a mechanical or necrotic nature. The content of alanine aminotransferase in the norm should not exceed 12-32 U / l in women, and for men, ALT activity in the range of 10-40 U / l is considered normal. An increase in ALT activity, achieved tenfold, may indicate the development infectious diseases organ, and even long before the appearance of their first symptoms.

Additional studies of the activity of liver enzymes are used, as a rule, for differential diagnosis. To do this, an analysis can be carried out for LDH, GGT and GlDH:

The norm of lactate dehydrogenase activity is an indicator ranging from 140-350 U / l.

Increased rates GDH can be a sign of dystrophic lesions of the organ, severe intoxication, diseases of an infectious nature or oncology. The maximum allowable indicator of such an enzyme for females is 3.0 U / l, and for men - 4.0 U / l.

The norm of GGT enzyme activity for men is up to 55 U / l, for women - up to 38 U / l. Deviations from this norm may indicate the development of diabetes, as well as diseases of the biliary tract. In this case, the enzyme activity index can increase tenfold. In addition, GGT in modern medicine is used to determine alcoholic hepatosis.

Enzymes synthesized by the liver have different functions. So, some of them, together with bile, are excreted from the organ through bile ducts and takes an active part in the process of digestion of food. A striking example of this is alkaline phosphatase. Normal the activity of this enzyme in the blood should be in the range of 30-90 U / l. It is worth noting that in males this figure can reach 120 U / l (with intensive metabolic processes, the figure may increase).

Blood enzymes

Determining the activity of enzymes and their content in the body is one of the main diagnostic methods in the definition of various diseases. Thus, blood enzymes contained in its plasma may indicate the development of liver pathologies, inflammatory and necrotic processes in tissue cells, diseases of the cardiovascular system, etc. Blood enzymes are usually divided into two groups. The first group includes enzymes released into the blood plasma by certain organs. For example, the liver produces the so-called precursors of enzymes necessary for the functioning of the blood coagulation system.

The second group has a much larger number of blood enzymes. In the body of a healthy person, such protein molecules do not have physiological significance in the blood plasma, since they act exclusively at the intracellular level in the organs and tissues that they produce. Normally, the activity of such enzymes should be low and constant. When cells are damaged, which is accompanied by various diseases, the enzymes contained in them are released and enter the bloodstream. The reason for this may be inflammatory and necrotic processes. In the first case, the release of enzymes occurs due to a violation of the permeability of the cell membrane, in the second - due to a violation of the integrity of the cells. At the same time, the higher the level of enzymes in the blood, the greater the degree of cell damage.

Biochemical analysis allows you to determine the activity of certain enzymes in blood plasma. It is actively used in the diagnosis of various diseases of the liver, heart, skeletal muscles and other types of tissues in the human body. In addition, the so-called enzyme diagnostics, when determining certain diseases, takes into account the subcellular localization of enzymes. The results of such studies allow us to determine exactly what processes occur in the body. Yes, at inflammatory processes in tissues, blood enzymes have a cytosolic localization, and with necrotic lesions, the presence of nuclear or mitochondrial enzymes is determined.

It should be noted that the increase in the content of enzymes in the blood is not always due to tissue damage. Active pathological proliferation of tissues in the body, in particular with cancer, increased production of certain enzymes, or a violation of the excretory ability of the kidneys can also be determined by an increased content of certain enzymes in the blood.

In modern medicine, a special place is given to the use of various enzymes for diagnostic and therapeutic purposes. Also, enzymes have found their application as specific reagents, which allow to accurately determine different substances. For example, when performing an analysis to determine the level of glucose in urine and blood serum, glucose oxidase is used in modern laboratories. Urease is used to assess the quantitative content of urea in urine and blood tests. Different types of dehydrogenases make it possible to accurately determine the presence of various substrates (lactate, pyruvate, ethyl alcohol, etc.).

The high immunogenicity of enzymes significantly limits their use for therapeutic purposes. But, despite this, the so-called enzyme therapy is actively developing, using enzymes (preparations with their content), as a means of replacement therapy or an element of complex treatment. Replacement therapy is used for diseases of the gastrointestinal tract, the development of which is caused by insufficient production of digestive juice. With a deficiency of pancreatic enzymes, their deficiency can be compensated by oral administration of drugs in which they are present.

As an additional element in complex treatment, enzymes can be used in various diseases. For example, proteolytic enzymes such as trypsin and chymotrypsin are used in the processing festering wounds. Preparations with the enzymes deoxyribonuclease and ribonuclease are used in the treatment of adenoviral conjunctivitis or herpetic keratitis. Enzyme preparations are also used in the treatment of thrombosis and thromboembolism, oncological diseases, etc. Their use is relevant for the resorption of burn contractures and postoperative scars.

The use of enzymes in modern medicine is very diverse and this area is constantly evolving, which allows us to constantly find new and more effective methods of treating certain diseases.

Often, along with vitamins, minerals and other elements useful for the human body, substances called enzymes are mentioned. What are enzymes and what function do they perform in the body, what is their nature and where are they located?

These are substances of protein nature, biocatalysts. Without them there would be no baby food, ready-made cereals, kvass, cheese, cheese, yogurt, kefir. They affect the functioning of all systems of the human body. Insufficient or excessive activity of these substances adversely affects health, so you need to know what enzymes are in order to avoid problems caused by their lack.

What it is?

Enzymes are protein molecules synthesized by living cells. There are more than a hundred of them in each cell. The role of these substances is colossal. They influence the course of the rate of chemical reactions at a temperature that is suitable for a given organism. Another name for enzymes is biological catalysts. An increase in the rate of a chemical reaction occurs by facilitating its flow. As catalysts, they are not consumed during the reaction and do not change its direction. The main functions of enzymes are that without them all reactions would proceed very slowly in living organisms, and this would noticeably affect viability.

For example, when chewing foods that contain starch (potatoes, rice), a sweetish taste appears in the mouth, which is associated with the work of amylase, an enzyme that breaks down starch present in saliva. By itself, starch is tasteless, as it is a polysaccharide. Its cleavage products (monosaccharides) have a sweet taste: glucose, maltose, dextrins.

All are divided into simple and complex. The former consist only of protein, while the latter consist of protein (apoenzyme) and non-protein (coenzyme) parts. Vitamins of groups B, E, K can be coenzymes.

Enzyme classes

Traditionally, these substances are divided into six groups. The name was originally given to them depending on the substrate on which a certain enzyme acts, by adding the ending -ase to its root. So, those enzymes that hydrolyze proteins (proteins) began to be called proteinases, fats (lipos) - lipases, starch (amilon) - amylases. Then the enzymes that catalyze similar reactions received names that indicate the type of the corresponding reaction - acylases, decarboxylases, oxidases, dehydrogenases, and others. Most of these names are still in use today.

Later, the International Biochemical Union introduced a nomenclature according to which the name and classification of enzymes should correspond to the type and mechanism of the chemical reaction catalyzed. This step brought relief in the systematization of data that relate to various aspects of metabolism. Reactions and the enzymes that catalyze them are divided into six classes. Each class consists of several subclasses (4-13). The first part of the name of the enzyme corresponds to the name of the substrate, the second - to the type of catalyzed reaction with the ending -aza. Each enzyme according to the classification (CF) has its own code number. The first digit corresponds to the reaction class, the next to the subclass, and the third to the subsubclass. The fourth digit indicates the number of the enzyme in order in its subclass. For example, if the EC is 2.7.1.1, then the enzyme belongs to the 2nd class, 7th subclass, 1st subclass. The last number refers to the enzyme hexokinase.

Meaning

If we talk about what enzymes are, we cannot ignore the question of their significance in the modern world. They are widely used in almost all branches of human activity. Such their prevalence is due to the fact that they are able to preserve their unique properties outside living cells. In medicine, for example, enzymes of the groups of lipases, proteases, and amylases are used. They break down fats, proteins, starch. As a rule, this type is part of such drugs as Panzinorm, Festal. These funds are primarily used to treat diseases of the gastrointestinal tract. Some enzymes are able to dissolve in blood vessels blood clots, they help in the treatment of purulent wounds. Enzyme therapy occupies a special place in the treatment of oncological diseases.

Due to its ability to break down starch, the enzyme amylase is widely used in the food industry. In the same area, lipases are used, which break down fats and proteases, which break down proteins. Amylase enzymes are used in brewing, winemaking and baking. In the preparation of ready-made cereals and to soften meat, proteases are used. In the production of cheese, lipases and rennet are used. The cosmetics industry also cannot do without them. They are part of washing powders, creams. In washing powders, for example, amylase, which breaks down starch, is added. Protein impurities and proteins are broken down by proteases, and lipases clean the tissue of oil and fat.

The role of enzymes in the body

Two processes are responsible in the human body for metabolism: anabolism and catabolism. The first ensures the absorption of energy and essential substances, the second - the breakdown of waste products. The constant interaction of these processes affects the absorption of carbohydrates, proteins and fats and the maintenance of the body's vital functions. Metabolic processes are regulated by three systems: nervous, endocrine and circulatory. They can function normally with the help of a chain of enzymes, which in turn ensure that a person adapts to changes in the conditions of the external and internal environment. Enzymes contain both protein and non-protein products.

In the process of biochemical reactions in the body, in the course of which enzymes take part, they themselves are not consumed. Each of them has its own chemical structure and its own unique role, so each initiates only a certain reaction. Biochemical catalysts help the rectum, lungs, kidneys, liver remove toxins and waste products from the body. They also contribute to the construction of skin, bones, nerve cells, muscle tissues. Specific enzymes are used to oxidize glucose.

All enzymes in the body are divided into metabolic and digestive. Metabolic are involved in the neutralization of toxins, the production of proteins and energy, and accelerate biochemical processes in cells. So, for example, superoxide dismutase is the strongest antioxidant, which is found naturally in most green plants, white cabbage, Brussels sprouts and broccoli, in wheat germ, greens, barley.

Enzyme activity

In order for these substances to fully perform their functions, certain conditions are necessary. Their activity is primarily affected by temperature. With increased, the rate of chemical reactions increases. As a result of the increase in the speed of the molecules, they are more likely to collide with each other, and the possibility of a reaction, therefore, increases. The optimal temperature provides the greatest activity. Due to the denaturation of proteins, which occurs when the optimal temperature deviates from the norm, the rate of a chemical reaction decreases. When the freezing point temperature is reached, the enzyme does not denature, but is inactivated. The quick freezing method, which is widely used for long-term storage of products, stops the growth and development of microorganisms, followed by inactivation of the enzymes that are inside. As a result, food does not decompose.

The activity of enzymes is also affected by the acidity of the environment. They work at neutral pH. Only some of the enzymes work in alkaline, strongly alkaline, acidic, or strongly acidic environments. For example, rennet breaks down proteins in the highly acidic environment of the human stomach. The enzyme can be affected by inhibitors and activators. Some ions, for example, metals, activate them. Other ions have a suppressive effect on the activity of enzymes.

Hyperactivity

Excessive activity of enzymes has its consequences for the functioning of the whole organism. First, it provokes an increase in the rate of enzyme action, which in turn causes a deficiency of the reaction substrate and the formation of an excess of the chemical reaction product. Deficiency of substrates and the accumulation of these products significantly worsens the state of health, disrupts the vital activity of the body, causes the development of diseases and can result in the death of a person. Accumulation of uric acid, for example, leads to gout and kidney failure. Due to the lack of substrate, there will be no excess product. This only works if one and the other can be dispensed with.

There are several reasons for the excess activity of enzymes. The first is a gene mutation; it can be congenital or acquired under the influence of mutagens. The second factor is an excess of a vitamin or trace element in water or food, which is necessary for the enzyme to work. An excess of vitamin C, for example, through the increased activity of collagen synthesis enzymes, disrupts the mechanisms of wound healing.

Hypoactivity

Both increased and decreased activity of enzymes negatively affects the activity of the body. In the second case, a complete cessation of activity is possible. This state dramatically reduces the rate of the chemical reaction of the enzyme. As a result, the accumulation of the substrate is complemented by a deficiency of the product, which leads to serious complications. Against the background of disturbances in the vital functions of the body, the state of health worsens, diseases develop, and there may be fatal outcome. Accumulation of ammonia or deficiency of ATP leads to death. Oligophrenia develops due to the accumulation of phenylalanine. The principle also applies here that in the absence of an enzyme substrate, there will be no accumulation of the reaction substrate. A bad effect on the body has a condition in which blood enzymes do not perform their functions.

Several causes of hypoactivity are considered. Mutation of genes, congenital or acquired - this is the first. The condition can be corrected with the help of gene therapy. You can try to exclude substrates of the missing enzyme from food. In some cases this may help. The second factor is the lack of a vitamin or trace element in the food necessary for the enzyme to work. The following causes are impaired vitamin activation, amino acid deficiency, acidosis, the appearance of inhibitors in the cell, protein denaturation. Enzyme activity also decreases with a decrease in body temperature. Some factors affect the function of all types of enzymes, while others only affect the work of certain types.

Digestive enzymes

A person enjoys the process of eating and sometimes ignores the fact that the main task of digestion is the transformation of food into substances that can become a source of energy and building material for the body, being absorbed into the intestines. Protein enzymes contribute to this process. Digestive substances are produced by the digestive organs, which are involved in the process of splitting food. The action of enzymes is necessary in order to obtain the necessary carbohydrates, fats, amino acids from food, which is the necessary nutrients and energy for the normal functioning of the body.

In order to normalize impaired digestion, it is recommended to simultaneously use the necessary protein substances with meals. When overeating, you can take 1-2 tablets after or during meals. Sold in pharmacies a large number of various enzyme preparations that help improve digestion. They should be stocked up when taking one type of nutrient. For problems with chewing or swallowing food, it is necessary to take enzymes with meals. Significant reasons for their use can also be diseases such as acquired and congenital fermentopathy, irritable bowel syndrome, hepatitis, cholangitis, cholecystitis, pancreatitis, colitis, chronic gastritis. Enzyme preparations should be taken along with drugs that affect the digestive process.

Enzymopathology

In medicine, there is a whole section that deals with the search for a connection between a disease and the lack of synthesis of a particular enzyme. This is the field of enzymology - enzymopathology. Insufficient enzyme synthesis is also to be considered. For example, hereditary disease phenylketonuria develops against the background of the loss of the ability of liver cells to synthesize this substance, which catalyzes the conversion of phenylalanine into tyrosine. Symptoms this disease are mental disorders. Due to the gradual accumulation of toxic substances in the patient's body, symptoms such as vomiting, anxiety, increased irritability, lack of interest in anything, severe fatigue are disturbing.

At the birth of a child, the pathology does not manifest itself. Primary symptoms can be noticed between the ages of two and six months. The second half of the baby's life is characterized by a pronounced lag in mental development. In 60% of patients, idiocy develops, less than 10% are limited to a mild degree of oligophrenia. Cell enzymes do not cope with their functions, but this can be corrected. Timely diagnosis of pathological changes can stop the development of the disease until puberty. Treatment consists in limiting the intake of phenylalanine with food.

Enzyme preparations

Answering the question of what enzymes are, two definitions can be noted. The first is biochemical catalysts, and the second is preparations that contain them. They are able to normalize the state of the environment in the stomach and intestines, ensure the breakdown of final products to microparticles, and improve the absorption process. They also prevent the emergence and development of gastroenterological diseases. The best known of the enzymes is medicinal product Mezim Forte. In its composition, it has lipase, amylase, protease, which help reduce pain in chronic pancreatitis. Capsules are taken as a replacement treatment for insufficient production of the necessary enzymes by the pancreas.

These drugs are mainly taken with meals. The number of capsules or tablets is prescribed by the doctor, based on the identified violations of the absorption mechanism. It is better to store them in the refrigerator. With prolonged use of digestive enzymes, addiction does not occur, and this does not affect the work of the pancreas. When choosing a drug, you should pay attention to the date, the ratio of quality and price. Enzyme preparations are recommended for chronic diseases of the digestive system, overeating, periodic stomach problems, and food poisoning. Most often, doctors prescribe the Mezim tablet preparation, which has proven itself well in the domestic market and confidently holds its position. There are other analogues of this drug, no less famous and more than affordable. In particular, many prefer Pacreatin or Festal tablets, which have the same properties as more expensive counterparts.

The life of any organism is possible due to the metabolic processes occurring in it. These reactions are controlled by natural catalysts, or enzymes. Another name for these substances is enzymes. The term "enzymes" comes from the Latin fermentum, which means "sourdough". The concept appeared historically in the study of fermentation processes.

Rice. 1 - Fermentation using yeast - a typical example of an enzymatic reaction

Mankind has long enjoyed the beneficial properties of these enzymes. For example, for many centuries, cheese has been made from milk using rennet.

Enzymes differ from catalysts in that they act in a living organism, while catalysts - in inanimate nature. The branch of biochemistry that studies these essential substances for life is called enzymology.

General properties of enzymes

Enzymes are protein molecules that interact with various substances, accelerating their chemical transformation along a certain path. However, they are not consumed. Each enzyme has an active site that attaches to a substrate and a catalytic site that starts a particular chemical reaction. These substances accelerate the biochemical reactions occurring in the body without raising the temperature.

The main properties of enzymes:

specificity: the ability of an enzyme to act only on a specific substrate, for example, lipases on fats;
catalytic efficiency: the ability of enzymatic proteins to accelerate biological reactions hundreds and thousands of times;
ability to regulate: in each cell, the production and activity of enzymes is determined by a peculiar chain of transformations that affects the ability of these proteins to be synthesized again.

The role of enzymes in the human body cannot be overestimated. At that time, when the structure of DNA had just been discovered, it was said that one gene is responsible for the synthesis of one protein, which already determines some particular trait. Now this statement sounds like this: "One gene - one enzyme - one trait." That is, without the activity of enzymes in the cell, life cannot exist.

Classification

Depending on the role in chemical reactions, the following classes of enzymes are distinguished:

In a living organism, all enzymes are divided into intra- and extracellular. Intracellular include, for example, liver enzymes involved in the neutralization reactions various substances coming with blood. They are found in the blood when an organ is damaged, which helps in the diagnosis of its diseases.

Intracellular enzymes that are markers of damage to internal organs:

liver - alanine aminotransferase, aspartate aminotransferase, gamma-glutamyl transpeptidase, sorbitol dehydrogenase;
kidneys - alkaline phosphatase;
prostate - acid phosphatase;
cardiac muscle - lactate dehydrogenase

Extracellular enzymes are secreted by glands during external environment. The main ones are secreted by the cells of the salivary glands, gastric wall, pancreas, intestines and are actively involved in digestion.

Digestive enzymes

Digestive enzymes are proteins that speed up the breakdown of large molecules that make up food. They divide such molecules into smaller fragments that are easier for cells to digest. The main types of digestive enzymes are proteases, lipases, and amylases.

The main digestive gland is the pancreas. It produces most of these enzymes, as well as nucleases that cleave DNA and RNA, and peptidases involved in the formation of free amino acids. Moreover, a small amount of enzymes formed is able to "process" a large amount of food.

During the enzymatic breakdown of nutrients, energy is released, which is consumed for metabolic processes and vital activity. Without the participation of enzymes, such processes would occur too slowly, not providing the body with a sufficient energy supply.

In addition, the participation of enzymes in the process of digestion ensures the breakdown of nutrients into molecules that can pass through the cells of the intestinal wall and enter the bloodstream.

Amylase

Amylase is produced by the salivary glands. It acts on food starch, which is made up of a long chain of glucose molecules. As a result of the action of this enzyme, sections are formed consisting of two connected glucose molecules, that is, fructose, and other short-chain carbohydrates. They are further metabolized to glucose in the intestines and from there absorbed into the blood.

The salivary glands break down only part of the starch. Salivary amylase is active for a short time while food is being chewed. After entering the stomach, the enzyme is inactivated by its acidic contents. Most of the starch is already broken down in the duodenum by the action of pancreatic amylase, produced by the pancreas.

Rice. 2 - Amylase starts the breakdown of starch

Short carbohydrates formed under the action of pancreatic amylase enter the small intestine. Here, with the help of maltase, lactase, sucrase, dextrinase, they are broken down to glucose molecules. Fiber that is not degraded by enzymes is excreted from the intestines with feces.

Proteases

Proteins or proteins are an essential part of the human diet. For their splitting enzymes - proteases are necessary. They differ in the site of synthesis, substrates, and other characteristics. Some of them are active in the stomach, such as pepsin. Others are produced by the pancreas and are active in the intestinal lumen. In the gland itself, an inactive enzyme precursor, chymotrypsinogen, is released, which begins to act only after mixing with acidic food contents, turning into chymotrypsin. This mechanism helps to avoid self-damage by proteases of pancreatic cells.

Rice. 3 - Enzymatic cleavage of proteins

Proteases break down food proteins into smaller fragments - polypeptides. Enzymes - peptidases break them down to amino acids that are absorbed in the intestines.

Lipases

Dietary fats are broken down by lipase enzymes, which are also produced by the pancreas. They break down fat molecules into fatty acids and glycerol. Such a reaction requires the presence in the lumen of the duodenum of bile, which is formed in the liver.

Rice. 4 - Enzymatic hydrolysis of fats

The role of replacement therapy with Mikrazim

For many people with digestive disorders, especially those with pancreatic diseases, the administration of enzymes provides functional support for the organ and speeds up the healing process. After stopping an attack of pancreatitis or another acute situation, the intake of enzymes can be stopped, as the body independently restores their secretion.

Long-term use of enzymatic preparations is necessary only in case of severe exocrine pancreatic insufficiency.

One of the most physiological in its composition is the drug "Mikrazim". It consists of amylase, proteases and lipase contained in pancreatic juice. Therefore, there is no need to separately select which enzyme should be used for various diseases of this organ.

Indications for the use of this medication:

chronic pancreatitis, cystic fibrosis and other causes of insufficient secretion of pancreatic enzymes;
inflammatory diseases of the liver, stomach, intestines, especially after operations on them, for faster recovery of the digestive system;
nutritional errors;
violation of the function of chewing, for example, with dental diseases or immobility of the patient.

Taking digestive enzymes for replacement purposes helps to avoid bloating, loose stools, and abdominal pain. In addition, in severe chronic diseases of the pancreas, Micrasim completely assumes the function of splitting nutrients. Therefore, they can be freely absorbed in the intestines. This is especially important for children with cystic fibrosis.

Important: before use, read the instructions or consult your doctor.

Enzymes are a special type of proteins that nature has assigned the role of catalysts for various chemical processes.

This term is constantly heard, however, not everyone understands what an enzyme or enzyme is, what functions this substance performs, and also how enzymes differ from enzymes and whether they differ at all. We'll find out all this now.

Without these substances, neither humans nor animals would be able to digest food. And for the first time, mankind resorted to the use of enzymes in everyday life more than 5 thousand years ago, when our ancestors learned to store milk in "dishes" from the stomachs of animals. Under such conditions, under the influence of rennet, milk turned into cheese. And this is just one example of the work of an enzyme as a catalyst, accelerating biological processes. Today, enzymes are indispensable in industry, they are important for the production of sugar, margarine, yogurt, beer, leather, textiles, alcohol and even concrete. AT detergents and washing powders also contain these beneficial substances - they help remove stains at low temperatures.

Discovery history

Enzyme in translation from Greek means "sourdough". And mankind owes the discovery of this substance to the Dutchman Jan Baptist Van Helmont, who lived in the 16th century. At one time he became very interested in alcoholic fermentation and during the study he found an unknown substance that accelerates this process. The Dutchman called it fermentum, which means fermentation. Then, almost three centuries later, the Frenchman Louis Pasteur, also observing fermentation processes, came to the conclusion that enzymes are nothing but the substances of a living cell. And after some time, the German Eduard Buchner extracted the enzyme from yeast and determined that this substance is not a living organism. He also gave him his name - "zimaza". A few years later, another German, Willy Kuehne, proposed to divide all protein catalysts into two groups: enzymes and enzymes. Moreover, he proposed to call the second term “sourdough”, the actions of which extend outside living organisms. And only 1897 put an end to all scientific disputes: it was decided to use both terms (enzyme and enzyme) as absolute synonyms.

Structure: a chain of thousands of amino acids

All enzymes are proteins, but not all proteins are enzymes. Like other proteins, enzymes are made up of . And interestingly, the creation of each enzyme takes from a hundred to a million amino acids strung like pearls on a string. But this thread is not even - it is usually bent hundreds of times. Thus, a three-dimensional structure unique for each enzyme is created. Meanwhile, the enzyme molecule is a relatively large formation, and only a small part of its structure, the so-called active center, is involved in biochemical reactions.

Each amino acid is connected to a specific type of chemical bond, and each enzyme has its own unique amino acid sequence. About 20 types of amino substances are used to create most of them. Even minor changes in the amino acid sequence can dramatically change the look and feel of an enzyme.

Biochemical properties

Although a huge number of reactions occur in nature with the participation of enzymes, they can all be grouped into 6 categories. Accordingly, each of these six reactions proceeds under the influence of a certain type of enzyme.

Reactions involving enzymes:

Oxidation and reduction.

The enzymes involved in these reactions are called oxidoreductases. As an example, remember how alcohol dehydrogenases convert primary alcohols to aldehyde.

Group transfer reaction.

The enzymes responsible for these reactions are called transferases. They have the ability to move functional groups from one molecule to another. This happens, for example, when alanine aminotransferases move alpha-amino groups between alanine and aspartate. Transferases also move phosphate groups between ATP and other compounds, and create disaccharides from glucose residues.

Hydrolysis.

The hydrolases involved in the reaction are able to break single bonds by adding elements of water.

Create or remove a double bond.

This type of reaction occurs in a non-hydrolytic way with the participation of lyase.

Isomerization of functional groups.

In many chemical reactions, the position of the functional group changes within the molecule, but the molecule itself is made up of the same number and types of atoms that it had before the reaction began. In other words, the substrate and product of the reaction are isomers. This type of transformation is possible under the influence of isomerase enzymes.

The formation of a single bond with the elimination of the element water.

Hydrolases break bonds by adding water elements to the molecule. Lyases carry out the reverse reaction, removing the aqueous part from the functional groups. Thus, a simple connection is created.

How they work in the body

Enzymes speed up almost all chemical reactions that occur in cells. They are of vital importance for humans, facilitate digestion and speed up metabolism.

Some of these substances help break down molecules that are too large into smaller "chunks" that the body can digest. Others, on the contrary, bind small molecules. But enzymes, scientifically speaking, are highly selective. This means that each of these substances is capable of accelerating only a certain reaction. The molecules that enzymes work with are called substrates. The substrates, in turn, form a bond with a part of the enzyme called the active site.

There are two principles that explain the specifics of the interaction of enzymes and substrates. In the so-called "key-lock" model, the active site of the enzyme occupies the place of a strictly defined configuration in the substrate. According to another model, both participants in the reaction, the active site and the substrate, change their shapes in order to connect.

Whatever the principle of the interaction, the result is always the same - the reaction under the influence of the enzyme proceeds many times faster. As a result of this interaction, new molecules are “born”, which are then separated from the enzyme. And the catalyst substance continues to do its job, but with the participation of other particles.

Hyper- and hypoactivity

There are times when enzymes perform their functions with the wrong intensity. Excessive activity causes excessive reaction product formation and substrate deficiency. As a result, deterioration in well-being and serious illness. Enzyme overactivity can be caused by genetic disorder, and an excess of vitamins or used in the reaction.

Enzyme hypoactivity can even cause death when, for example, enzymes do not remove toxins from the body or ATP deficiency occurs. The cause of this condition can also be mutated genes or, conversely, hypovitaminosis and a deficiency of other nutrients. Besides, low temperature body likewise slows down the functioning of enzymes.

Catalyst and more

Today you can often hear about the benefits of enzymes. But what are these substances on which the performance of our body depends?

Enzymes are biological molecules life cycle which is not defined by the framework of birth and death. They just work in the body until they dissolve. As a rule, this occurs under the influence of other enzymes.

In the course of a biochemical reaction, they do not become part of the final product. When the reaction is complete, the enzyme leaves the substrate. After that, the substance is ready to start working again, but on a different molecule. And so it goes on for as long as the body needs.

The uniqueness of enzymes is that each of them performs only one assigned function. A biological reaction occurs only when the enzyme finds the right substrate for it. This interaction can be compared with the principle of operation of a key and a lock - only correctly selected elements can work together. Another feature: they can work at low temperatures and moderate pH, and as catalysts they are more stable than any other chemicals.

Enzymes as catalysts speed up metabolic processes and other reactions.

As a rule, these processes consist of certain stages, each of which requires the work of a certain enzyme. Without this, the transformation or acceleration cycle cannot be completed.

Perhaps the most well-known of all the functions of enzymes is the role of a catalyst. This means that enzymes combine chemical reagents in such a way as to reduce the energy costs required to form a product more quickly. Without these substances, chemical reactions would proceed hundreds of times slower. But the abilities of enzymes do not end there. All living organisms contain the energy they need to continue living. Adenosine triphosphate, or ATP, is a kind of charged battery that supplies energy to cells. But the functioning of ATP is impossible without enzymes. And the main enzyme that produces ATP is synthase. For each glucose molecule that is converted into energy, synthase produces about 32-34 ATP molecules.

In addition, enzymes (lipase, amylase, protease) are actively used in medicine. In particular, they serve as a component of enzymatic preparations, such as Festal, Mezim, Panzinorm, Pancreatin, used to treat indigestion. But some enzymes can also affect circulatory system(dissolve blood clots), accelerate the healing of purulent wounds. And even in anti-cancer therapy, they also resort to the help of enzymes.

Factors that determine the activity of enzymes

Since the enzyme is able to speed up reactions many times over, its activity is determined by the so-called turnover number. This term refers to the number of substrate molecules (reactive substances) that 1 enzyme molecule can transform in 1 minute. However, there are a number of factors that determine the rate of a reaction:

substrate concentration.

Increasing the substrate concentration leads to an acceleration of the reaction. The more molecules active ingredient, the faster the reaction proceeds, since more active centers. However, acceleration is possible only until all enzyme molecules are involved. After that, even increasing the concentration of the substrate will not accelerate the reaction.

Temperature.

Usually, an increase in temperature leads to an acceleration of reactions. This rule works for most enzymatic reactions, but only as long as the temperature does not rise above 40 degrees Celsius. After this mark, the reaction rate, on the contrary, begins to decrease sharply. If the temperature drops below a critical point, the rate of enzymatic reactions will increase again. If the temperature continues to rise, the covalent bonds are broken and the catalytic activity of the enzyme is lost forever.

Acidity.

The rate of enzymatic reactions is also affected by the pH value. Each enzyme has its own optimal level of acidity, at which the reaction proceeds most adequately. Changing the pH level affects the activity of the enzyme, and hence the rate of the reaction. If the change is too great, the substrate loses its ability to bind to the active nucleus, and the enzyme can no longer catalyze the reaction. With the restoration of the required pH level, the activity of the enzyme is also restored.

Enzymes present in the human body can be divided into 2 groups:

metabolic;
digestive.

Metabolic "work" to neutralize toxic substances, and also contribute to the production of energy and proteins. And, of course, they accelerate the biochemical processes in the body.

What the digestive organs are responsible for is clear from the name. But even here the principle of selectivity works: a certain type of enzyme affects only one type of food. Therefore, to improve digestion, you can resort to a little trick. If the body does not digest something from food well, then it is necessary to supplement the diet with a product containing an enzyme that can break down hard-to-digest food.

Food enzymes are catalysts that break down food to a state in which the body is able to absorb useful substances from them. Digestive enzymes come in several types. In the human body, different types of enzymes are found in different parts of the digestive tract.

Oral cavity

At this stage, alpha-amylase acts on the food. It breaks down carbohydrates, starches and glucose found in potatoes, fruits, vegetables and other foods.

Stomach

Here, pepsin breaks down proteins into peptides, and gelatinase breaks down the gelatin and collagen found in meat.

Pancreas

At this stage, "work":

trypsin - responsible for the breakdown of proteins;
alpha-chymotrypsin - helps the absorption of proteins;
elastase - break down certain types of proteins;
nucleases - help break down nucleic acids;
steapsin - promotes the absorption of fatty foods;
amylase - responsible for the absorption of starches;
lipase - breaks down fats (lipids) found in dairy products, nuts, oils, and meats.

Small intestine

Over food particles "conjure":

peptidases - break down peptide compounds to the level of amino acids;
sucrase - helps to absorb complex sugars and starches;
maltase - breaks down disaccharides to the state of monosaccharides (malt sugar);
lactase - breaks down lactose (glucose found in dairy products);
lipase - promotes the absorption of triglycerides, fatty acids;
erepsin - affects proteins;
isomaltase - "works" with maltose and isomaltose.

Colon

Here the functions of enzymes are performed:

coli - responsible for the digestion of lactose;
lactobacilli - affect lactose and some other carbohydrates.

In addition to these enzymes, there are also:

diastase - digests vegetable starch;
invertase - breaks down sucrose (table sugar);
glucoamylase - converts starch into glucose;
alpha-galactosidase - promotes the digestion of beans, seeds, soy products, root vegetables and leafy vegetables;
bromelain - an enzyme derived from, promotes the breakdown different types proteins, effective at different levels of acidity of the environment, has anti-inflammatory properties;
papain, an enzyme isolated from raw papaya, promotes the breakdown of small and large proteins, is effective in a wide range of substrates and acidity.
cellulase - breaks down cellulose, plant fibers (not found in the human body);
endoprotease - cleaves peptide bonds;
ox bile extract - an enzyme of animal origin, stimulates intestinal motility;
pancreatin - an enzyme of animal origin, accelerates the digestion of proteins;
pancrelipase - an animal enzyme, promotes the absorption, and lipids;
pectinase - breaks down the polysaccharides contained in fruits;
phytase - promotes the absorption of phytic acid and other minerals;
xylanase - breaks down glucose from cereals.

Catalysts in products

Enzymes are critical to health because they help the body break down food components into a state suitable for nutrient use. The intestines and pancreas produce a wide range of enzymes. But besides this, many of their beneficial substances that promote digestion are also found in some products.

Fermented foods are an almost ideal source beneficial bacteria, necessary for proper digestion. And while pharmacy probiotics "work" only in the upper digestive system and often do not reach the intestines, the effect of enzymatic products is felt throughout the gastrointestinal tract.

For example, apricots contain a mixture of beneficial enzymes, including invertase, which is responsible for the breakdown of glucose and promotes rapid energy release.

Avocado can serve as a natural source of lipase (promotes faster digestion of lipids). In the body, this substance is produced by the pancreas. But in order to make life easier for this body, you can treat yourself, for example, to a salad with avocado - tasty and healthy.

In addition to being perhaps the best-known source of potassium, the banana also supplies amylase and maltase to the body. Amylase is also found in bread, potatoes, cereals. Maltase aids in the breakdown of maltose, the so-called malt sugar, which is abundant in beer and corn syrup.

Another exotic fruit - pineapple contains a whole range of enzymes, including bromelain. And it, according to some studies, also has anti-cancer and anti-inflammatory properties.

Extremophiles and industry

Extremophiles are substances that can survive in extreme conditions.

Living organisms, as well as the enzymes that enable them to function, have been found in geysers where the temperature is close to the boiling point, and deep in ice, as well as in conditions of extreme salinity (Death Valley in the USA). In addition, scientists have found enzymes for which the pH level, as it turned out, is also not a fundamental requirement for effective work. Researchers are studying extremophile enzymes with particular interest as substances that can be widely used in industry. Although even today enzymes have already found their application in the industry as biologically and environmentally friendly substances. The use of enzymes is resorted to in the food industry, cosmetology, and the production of household chemicals.

Moreover, the "services" of enzymes in such cases are cheaper than synthetic analogues. In addition, natural substances are biodegradable, which makes their use safe for the environment. In nature, there are microorganisms that can break down enzymes into individual amino acids, which then become components of a new biological chain. But that, as they say, is a completely different story.

These are substances of protein nature, biocatalysts. Without them, there would be no baby food, ready-made cereals, kvass, cheese, cheese, yogurt, kefir. They affect the functioning of all systems of the human body. Insufficient or excessive activity of these substances adversely affects health, so you need to know what enzymes are in order to avoid problems caused by their lack.

What it is?

Enzyme classes

Meaning

If we talk about what enzymes are, we cannot ignore the question of their significance in the modern world. They are widely used in almost all branches of human activity. Such their prevalence is due to the fact that they are able to preserve their unique properties outside living cells. In medicine, for example, enzymes of the groups of lipases, proteases, and amylases are used. They break down fats, proteins, starch. As a rule, this type is part of such drugs as Panzinorm, Festal. These funds are primarily used to treat diseases of the gastrointestinal tract. Some enzymes are able to dissolve blood clots in blood vessels, they help in the treatment of purulent wounds. Enzyme therapy occupies a special place in the treatment of oncological diseases.

The role of enzymes in the body

Enzyme activity

Hyperactivity

Excessive activity of enzymes has its consequences for the functioning of the whole organism. First, it provokes an increase in the rate of enzyme action, which in turn causes a deficiency of the reaction substrate and the formation of an excess of the chemical reaction product. Deficiency of substrates and the accumulation of these products significantly worsens the state of health, disrupts the vital activity of the body, causes the development of diseases and can result in the death of a person. The accumulation of uric acid, for example, leads to gout and kidney failure. Due to the lack of substrate, there will be no excess product. This only works if one and the other can be dispensed with.

Hypoactivity

Both increased and decreased activity of enzymes negatively affects the activity of the body. In the second case, a complete cessation of activity is possible. This state dramatically reduces the rate of the chemical reaction of the enzyme. As a result, the accumulation of the substrate is complemented by a deficiency of the product, which leads to serious complications. Against the background of disturbances in the vital functions of the body, the state of health worsens, diseases develop, and there may be a fatal outcome. Accumulation of ammonia or deficiency of ATP leads to death. Oligophrenia develops due to the accumulation of phenylalanine. The principle also applies here that in the absence of an enzyme substrate, there will be no accumulation of the reaction substrate. A bad effect on the body has a condition in which blood enzymes do not perform their functions.

Digestive enzymes

In order to normalize impaired digestion, it is recommended to simultaneously use the necessary protein substances with meals. When overeating, you can take 1-2 tablets after or during meals. Pharmacies sell a large number of different enzyme preparations that help improve digestion. They should be stocked up when taking one type of nutrient. For problems with chewing or swallowing food, it is necessary to take enzymes with meals. Significant reasons for their use can also be diseases such as acquired and congenital fermentopathy, irritable bowel syndrome, hepatitis, cholangitis, cholecystitis, pancreatitis, colitis, chronic gastritis. Enzyme preparations should be taken along with drugs that affect the digestive process.

Enzymopathology

In medicine, there is a whole section that deals with the search for a connection between a disease and the lack of synthesis of a particular enzyme. This is the field of enzymology - enzymopathology. Insufficient enzyme synthesis is also to be considered. For example, the hereditary disease phenylketonuria develops against the background of the loss of the ability of liver cells to synthesize this substance, which catalyzes the conversion of phenylalanine into tyrosine. Symptoms of this disease are disorders of mental activity. Due to the gradual accumulation of toxic substances in the patient's body, symptoms such as vomiting, anxiety, increased irritability, lack of interest in anything, severe fatigue are disturbing.

Enzyme preparations

Answering the question of what enzymes are, two definitions can be noted. The first is biochemical catalysts, and the second is preparations that contain them. They are able to normalize the state of the environment in the stomach and intestines, ensure the breakdown of final products to microparticles, and improve the absorption process. They also prevent the emergence and development of gastroenterological diseases. The most famous of the enzymes is the drug Mezim Forte. In its composition, it has lipase, amylase, protease, which help reduce pain in chronic pancreatitis. Capsules are taken as a replacement treatment for insufficient production of the necessary enzymes by the pancreas.