What are biological catalysts called? Enzymes as biological catalysts

The human body is called a biochemical factory for nothing. After all, every minute thousands, tens and hundreds of thousands of processes of oxidation, decomposition, reduction, and other reactions take place in it. What allows them to flow at such an enormous speed, providing each cell with energy, nutrition and oxygen?

The concept of catalysts

Both inorganic and organic chemistry, special substances are very widely used that can accelerate the flow of chemical reactions by several thousand, and sometimes millions of times. 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 temporary complexes with participants in the reaction, due to a decrease in the activation energy, the process is several times faster. After this, the complex decomposes, 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 options for catalytic reactions:

• homogeneous - an accelerator and participants in one aggregate state;
• heterogeneous - an accelerator and participants in different states; there is a phase boundary.

In addition, there are also opposite in action compounds - inhibitors. They are aimed at slowing down the necessary reactions. So, for example, they can reduce the amount of time for the formation of corrosion.

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

Enzymes - what is it?

It was proved that if the action of special substances accelerating the indicated processes were not carried out inside living systems, then an ordinary apple in the stomach would be digested for about two days. In such an amount of time, decomposition processes and intoxication with decay products would begin. However, this does not happen, and the fruit is fully processed in an hour and a half. This is carried out by biological catalysts, which are present in large numbers in the composition of each organism. But what are they and what is the basis of such an action?

Biological catalysts of a protein nature are enzymes. 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 speed that exceeds normal values ​​by several million times.

There are many examples of such molecules:

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

Thus, we can conclude: enzymes are biological catalysts of a protein nature that act as strong accelerators, allowing thousands of processes to be carried out in living organisms at a very high speed. Digestion, oxidation, and recovery are based on their action.

The similarities between inorganic and protein catalysts

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

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

However, in addition to 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 group of similar ones. Most often, the scheme "enzyme - substrate of a single process."
2. Extremely high degree of activity, because some types of proteins can accelerate reactions by a factor of millions.
3. Enzymes are highly dependent on environmental conditions. They are active only in a certain temperature range. The pH of the medium is also strongly affected. There is a curve showing the minimum, maximum, and optimum values ​​for each enzyme.
4. There are special compounds called effectors that can inhibit the nature of biological catalysts or, conversely, positively influence them.
5. The substrate on which the enzyme works must be strictly specific. There is a theory called key and lock. It describes the mechanism of action of the enzyme on the substrate. The catalyst, like a key, is embedded in the substrate with its active center, and the reaction begins.
6. After the process, the enzyme is partially or completely destroyed.

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

Studying Catalysis at School

As part of the school curriculum, catalysts are studied both in chemistry and in biology. At chemistry lessons, they are studied from the point of view of substances that allow industrial syntheses to be carried out and a large number of various products to be obtained. In biology classes, it is biological catalysts that are considered. Grade 9 involves the study of molecular biology and the fundamentals of biochemistry. Therefore, it is at this stage of education that students receive the basics of knowledge about enzymes as active substances in living organisms.

The lessons are experiments that confirm the chemical activity of these substances in certain temperature ranges and pH:

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

Enzymes in the human body

Every student who is sufficiently educated and has crossed the line of secondary education knows what biological catalysts are called. Enzymes in the body have a strictly specific specialization. Therefore, for each process, you can name your catalytic substance.

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

• oxidoreductases, for example, catalase or alcohol dehydrogenase;
• transferases - kenase;
• hydrolases important for digestion: pepsin, amylase, lipoprotein lipase, esterase and others;
• ligases, for example, DNA polymerase;
• isomerase;
• lyases.

Since all these compounds have a protein nature, as well as a complex of vitamins in the composition, an 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, high body temperature must be brought down during an illness.

The use of protein catalysts in industry

Often, enzymes are used in various industries :

• chemical;
• textile;
• food.

On the shelves of stores you can see cleaning products and washing powders containing enzymes - these are enzymes that improve the quality of washing clothes.

What are biological catalysts for?

It is difficult to overestimate their significance. 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 medicine, protect and protect our health and the environment.