What are the biological catalysts called? Enzymes as biological catalysts

Человеческий организм называют биохимической the factory is not for nothing. After all, every minute there are thousands, tens and hundreds of thousands of processes of oxidation, splitting, reduction and other reactions. What allows them to flow at such a tremendous speed, providing each cell with energy, nutrition and oxygen?

Concept of catalysts

Both inorganic and organic chemistrySpecial substances capable of accelerating the course of chemical reactions several thousand and sometimes millions of times are very widely used. The name of these compounds is "catalysts". In inorganic chemistry these are metal oxides, platinum, silver, nickel, and others.

Their main action is the formation of temporarycomplexes with participants of the reaction, due to a decrease in the activation energy, the process is carried out several times faster. After that, the complex breaks down, and the catalyst can be removed from the sphere in the same quantitative and qualitative composition as before the start of the process.

There are two types of catalytic reactions:

• homogeneous - accelerator and participants in one aggregative state;
• heterogeneous - accelerator and participants in different states, there is a phase separation line.

In addition, there are opposing actions.compounds - inhibitors. They are aimed at slowing down the necessary reactions. For example, they allow to reduce the amount of time for the formation of corrosion.

Biological catalysts are inherently different from inorganic, and their properties are somewhat specific. Therefore, in living systems, catalysis is different.

Enzymes - what is it?

It is proved that if the action of specialsubstances that accelerate the indicated processes were not carried out inside living systems, then a normal apple in the stomach would be digested for about two days. For such an amount of time, decomposition and intoxication with rotting products would begin. However, this does not happen, and the fruit is fully processed in half an hour. It is carried out by biological catalysts, which are present in large quantities in the composition of each organism. But what are they and what is such an action based on?

Biological catalysts of protein nature areenzymes. Their basis is a complex structural organization with a number of specific properties. Simply put, these are unique proteins that can reduce the activation energy of processes in living organisms and carry them out at a rate exceeding normal values ​​several million times.

Many examples of such molecules can be cited:

• catalase;
• amylase;
• oxidoreductase;
• glucose oxidase;
• lipase;
• invertase;
• lysozyme;
• protease and others.

Thus, we can conclude:Enzymes are biological catalysts of protein nature, which act as powerful accelerators, allowing thousands of processes in living organisms to be carried out at a very high speed. On their action is based digestion, oxidation, recovery.

The similarities of inorganic and protein catalysts

Enzymes as biological catalysts have a number of properties similar to inorganic. These include the following:

1. Accelerate only thermodynamically possible reactions.
2. They do not affect the shift of chemical equilibrium in equilibrium systems, but they equally accelerate both the direct and reverse processes.
3. As a result, only products remain in the scope of the reaction, the catalyst is not included in their number.

However, in addition to the similarity, there are also distinctive features of enzymes.

Differences depending on nature

Biological catalysts have several specific features:

1. High degree of selectivity. That is, one protein is able to activate only some specific reaction or a group of similar ones. Most often the scheme "enzyme - substrate of one process" works.
2. An extremely high degree of activity, because some types of proteins are able to accelerate the reaction millions of times.
3. Enzymes are highly dependent on environmental conditions.They are active only in a certain temperature range. Also strongly influenced by pH. There is a curve showing the values ​​of the minimum, maximum and optimum in terms of indicators for each enzyme.
4. There are special compounds called effectors that can inhibit the nature of biological catalysts or, conversely, have a positive effect on them.
5. The substrate on which the enzyme works mustbe strictly specific. There is a theory that is called a key and a lock. It describes the mechanism of action of the enzyme on the substrate. The catalyst, like the key, is embedded in the substrate at its active center, and the reaction begins.
6. After the process, the enzyme is partially or completely destroyed.

Thus, it is obvious that the importance of protein catalysts is extremely high for living organisms. However, their action is subject to certain rules and is limited by the framework of environmental conditions.

Studying catalysis in school

As part of the school program catalystsstudied in chemistry and biology. In chemistry classes, they are studied from the point of view of substances that allow industrial syntheses to produce a large number of various products. Biology lessons deal with biology lessons. Grade 9 involves the study of molecular biology and the basics of biochemistry. Therefore, it is at this stage of education that students acquire the basics of knowledge about enzymes as active substances in living organisms.

At the lessons, experiments are conducted confirming the chemical activity of these substances in certain temperature ranges and pH:

• investigation of the effect of hydrogen peroxide as a catalyst on raw and boiled carrots;
• impact on meat (processed thermally and raw), potatoes and other products.

Enzymes in the human body

Every student who is educated enough andpassed the boundary of the middle link of education, knows what biological catalysts are called. Enzymes in the body have strictly specific specialization. Therefore, for each process can be called its catalyzing substance.

So, all the body's enzymes can be divided into several groups:

• oxidoreductases such as catalase or alcohol dehydrogenase;
• transferase - kenase;
• hydrolases important for digestion: pepsin, amylase, lipoprotein lipase, esterase, and others;
• ligase, for example, DNA polymerase;
• isomerase;
• LiAZ.

Since all of these compounds have proteinnature, as well as a complex of vitamins in the composition, the increase in body temperature is fraught with denaturation of the structure, and therefore, the termination of all biochemical reactions. In this case, the body is close to death. Therefore, the high body temperature necessarily knock during illness.

Use of protein catalysts in industry

Often enzymes are used in various industries:

• chemical;
• textile;
• food.

On the shelves you can see cleaning products and laundry detergents containing enzymes - these are enzymes that improve the quality of laundry.

What are biological catalysts for?

It is difficult to overestimate their value.After all, they not only allow living organisms to live, breathe, eat, carry out metabolic processes, but also give us the opportunity to destroy industrial waste, get medicines, protect and protect our health and the environment.