Enzymes and Classification

The human body is made up of a variety of different types of cells, tissues, and other intricately designed organs. In order to function efficiently, our bodies release chemicals that speed up biological processes such as respiration, digestion, excretion, and a few other metabolic activities that are necessary to maintain a healthy lifestyle. As a result, enzymes are essential in all living organisms because they regulate all biological processes.

Enzymes

“Enzymes can be thought of as biological polymers that catalyse biochemical reactions,” explains the scientist.

The vast majority of enzymes are proteins with catalytic capabilities that are essential for the performance of various processes. The metabolic processes and other chemical reactions that occur in the cell are carried out by a group of enzymes that are required for the cell to function properly.

The enzymes are responsible for the first stage of the metabolic process, which involves reacting with a molecule known as the substrate in order to produce energy. Enzymes are molecules that convert substrates into other distinct molecules, which are referred to as products.Because of their importance in the maintenance of life processes, the regulation of enzymes has long been recognised as a critical component of clinical diagnosis. 

With the exception of the ribozymes, which are a class of RNA catalysts, all enzymes contain protein as their macromolecular constituents. Because of the ribonucleic acid enzyme in its name, the term “ribozyme” was coined. There are many types of ribozymes, which are ribonucleic acid molecules that catalyse reactions in one of their own bonds or between other RNAs.

The Structure of an Enzyme

Enzymes are made up of a linear chain of amino acids that combine to form a three-dimensional structure when heated. The structure of an enzyme is determined by the amino acid sequence, which in turn is determined by the catalytic activity of the enzyme. When heated, the structure of the enzyme denatures, resulting in a reduction in enzyme activity, which is typically associated with increased temperature.

The size of enzymes is typically large in comparison to their substrates, with sizes ranging from 62 amino acid residues in the case of a protein to an average of 2500 residues in the case of fatty acid synthase. During catalysis, only a small section of the structure is involved, and it is located close to one of the binding sites. The active site of an enzyme is formed by the catalytic site and the binding site working together. There are only a few ribozymes in existence, and they function as RNA-based biological catalysts. It reacts with proteins only when they are complex.

Amino acids

Previously, enzymes were given names based on the person who discovered the enzyme. The classification system became more comprehensive as more research was conducted.

According to the International Union of Biochemists (I U B), enzymes are classified into six functional classes based on the type of reaction that they are used to catalyse and are further subdivided into subclasses based on the type of reaction that they are used to catalyse. Hydrolases, oxidoreductases, lyases, transferases, ligases, and isomerases are among the six types of enzymes that exist.

Oxidoreductases

In the body, these enzymes catalyse oxidation and reduction reactions, for example, the oxidation of pyruvate to acetyl coenzyme A, which occurs in the presence of pyruvate dehydrogenase.

Transferases

These are catalysts that aid in the transfer of chemical groups from one compound to another. One such enzyme is a transaminase, which is responsible for the transfer of an amino group from one molecule to another.

Hydrolases

They are responsible for the hydrolysis of a bond. Pepsin, for example, is an enzyme that hydrolyzes peptide bonds found in proteins.

Lyases

For example, aldolase (an enzyme in glycolysis) catalyses the splitting of fructose-1, 6-bisphosphate into glyceraldehyde-3-phosphate and dihydroxyacetone phosphate without requiring the use of a catalytic agent.

Isomerases

They aid in the formation of an isomer of a compound by catalysing the reaction. In glycogenolysis, for example, phosphoglucomutase catalyses the conversion of glucose-1-phosphate to glucose-6-phosphate (in which the phosphate group is transferred from one position in the same compound to another position in the same compound) (glycogen is converted to glucose for energy to be released quickly).

Ligases

Ligases are enzymes that catalyse the joining of two molecules. For example, DNA ligase is a protein that catalyses the joining of two DNA fragments by forming a phosphodiester bond between them.

Cofactors

Cofactors are non-proteinaceous substances that interact with enzymes and aid in their function. An enzyme’s ability to function is dependent on the presence of a cofactor. Apoenzymes are enzymes that do not require the presence of a cofactor. The holoenzyme is made up of an enzyme and a cofactor that work together.

The cofactors that are present in enzymes are classified into three categories:

Proprietary groups: These are cofactors that are permanently bound to an enzyme at all times. A fad is a prosthetic group that can be found in a variety of enzymes.

Coenzyme: A coenzyme is a molecule that binds to an enzyme only during the catalytic process. During the rest of the time, it is completely separated from the enzyme. NAD+ is a coenzyme that is commonly found.

Metal ions: A metal ion is required at the active site of certain enzymes in order for them to catalyse the formation of coordinate bonds. Several enzymes require the metal ion cofactor Zn2+ which is a metal ion cofactor.

Enzymes are used in a variety of applications.

The following are some examples of enzymes in action:

Conclusion

They aid in the formation of an isomer of a compound by catalysing the reaction. In glycogenolysis, for example, phosphoglucomutase catalyses the conversion of glucose-1-phosphate to glucose-6-phosphate (in which the phosphate group is transferred from one position in the same compound to another position in the same compound) (glycogen is converted to glucose for energy to be released quickly).