Types of Enzymes

Table of Contents

Introduction

The human body is made up of many types of cells, tissues, and other complex organs. In order to function properly, our body releases certain chemicals to speed up biological processes such as respiration, digestion, excretion, and a few other metabolic functions to maintain good health. Thus, enzymes are essential for all living organisms that regulate all biological processes.

Many protein enzymes have the ability to perform various processes. Metabolic processes and other chemical reactions in a cell are made into a set of enzymes needed to sustain life.

The first phase of the metabolic process relies on enzymes, which react with a molecule and are called the substrate. Enzymes convert substrates into different molecules and are called products.

Enzyme control has become an important factor in clinical diagnosis because of its role in maintaining healthy processes. The macromolecular components of all enzymes contain proteins, with the exception of a class of RNA catalysts called ribozymes. The name ribozyme is derived from the ribonucleic acid enzyme. Many ribozyme molecules are ribonucleic acid molecules, which cause reactions in one of their bonds or among other RNA.

Enzymes are found in all tissues and body fluids. Catalysis of all reactions that occur in metabolic pathways is performed by intracellular enzymes. Enzymes in plasma membranes regulate catalysis in cells as a response to cellular signals and enzymes in the circulatory system that regulate blood clotting. Many of the most important health processes are established in the activities of enzymes.

Enzyme Structure

Enzymes are a series of amino acids, which create a three-dimensional structure. The amino acid sequence determines the formation, which also determines the catalytic activity of the enzyme. When heated, the enzyme structure changes, leading to loss of enzyme activity, which is often associated with temperature.

Compared to its substrates, the enzymes are usually large in varying sizes, ranging from 62 amino acid residues to an average of 2,500 residues found in fatty acid synthase. Only a small portion of the structure is involved in catalysis and is located close to the binding areas. The catalytic domain and the binding domain form an active enzyme site. There are a small number of ribozymes that act as RNA-based biological catalysts. It reacts complexly with proteins.

Enzyme Classification

Previously, enzymes were given names based on who received them. With further research, the classification has become more consistent.

According to the International Union of Biochemists (I U B), enzymes are divided into six active classes and are classified based on the type of reaction in which they are used to form a catalyze. Six types of enzymes are hydrolases, oxidoreductases, lyases, transferases, ligases, and isomerases.

Below is a breakdown of the enzymes discussed in detail:

Oxidoreductases
This promotes oxidation and reduction reactions, e.g. Pyruvate dehydrogenase, which causes the release of pyruvate into acetyl coenzyme A.
Transferases
These promote the transfer of a group of chemicals from one another to another. An example is a transaminase, which transfers an amino group from one molecule to another.
Hydrolases
They perform bond hydrolysis. For example, the enzyme pepsin hydrolyzes the peptide bonds in proteins.
Lyases
This creates a breakdown of bonds without catalysis, e.g. Aldolase (an enzyme in glycolysis) causes the separation of fructose-1, 6-bisphosphate to glyceraldehyde-3-phosphate and dihydroxyacetone phosphate.
Isomerase
They form the composition of the composite isomer. For example, phosphoglucomutase promotes the conversion of glucose-1-phosphate to glucose-6-phosphate (the phosphate group is transferred from one place to another in the same place) to glycogenolysis (glycogen is converted to sugar so that energy can be released quickly).
Ligases
The ligases create a combination of two molecules. For example, DNA gas promotes the fusion of two pieces of DNA by forming a phosphodiester bond.

Enzyme Inhibition

An enzyme inhibitor is a molecule that disrupts the normal reaction process between an enzyme and a substrate.

Enzyme inhibitors can be competitive or non-competitive depending on their mechanism of action

Types of Enzyme Inhibition

Enzyme inhibitors inhibit the formation of an enzyme-substrate complex and thus inhibit product formation.

Enzyme inhibition may be reversible or non-reversible depending on the specific effect of the inhibitor used.

Normal Enzyme Reaction

In a typical reaction, the substrate binds to the enzyme (through the active site) to form an enzyme-substrate complex.
The shape and structure of the substrate and the active site are related, leading to enzyme-substrate specification.
When binding occurs, the active site undergoes a corresponding change in order to interact well with the substrate (incorporated equation)
This change in alignment activates the chemical bonds within the substrate, reducing the initiating power
As a result of enzyme interaction, the substrate is converted into a rapid-rate product.

Competitive Inhibition

Inhibition of competition involves a molecule, other than a substrate, that binds to the active site of the enzyme.
A molecule (inhibitor) structurally and chemically like a substrate (hence the ability to bind to a functional area)
A competitive inhibitor blocks the active site and thus prevents substrate binding
As the inhibitor competes with the substrate, its effects can be reduced by increasing the concentration of the substrate

Non-Competitive Prohibition

Non-competitive blockchain involves a molecule binding to a site outside the active domain (allosteric domain)
The binding of an inhibitor in the allosteric zone causes a corresponding change in the active site of the enzyme.
As a result of this change, the active site and substrate do not share certain information, which means that the substrate cannot merge.
Since the inhibitor is not in direct competition with the substrate, increasing substrate levels cannot reduce the inhibitor effect.

Examples of Enzyme inhibition

Enzyme inhibitors can serve a variety of purposes, including medical (disease) and agriculture (such as pesticides).

An example of the use of a competitive inhibitor is in the treatment of fever with a neuraminidase inhibitor, RelenzaTM.

An example of the use of a non-competitive inhibitor is the use of cyanide as a poison (aerobic respiratory inhibitor)

Relenza (Competitive Inhibitor)

Relenza is a synthetic drug developed by Australian scientists to treat people infected with the H5N1 virus
Virions are released from infected cells when the viral enzyme neuraminidase breaks down the docking protein (hemagglutinin)
Relenza binds competitively to the active site of neuraminidase and prevents the breakdown of protein binding.
Therefore, virions are not released into infected cells, preventing the spread of the flu virus

Cyanide (Noncompetitive Inhibitor)

Cyanide is a toxin that inhibits ATP production through aerobic respiration, leading to eventual death
It binds to the allosteric component of cytochrome oxidase – a carrying molecule that forms part of the electron transport chain.
By changing the structure of the active site, cytochrome oxidase will no longer be able to transfer electrons to the final receptor (oxygen).
As a result, the electron transport chain cannot continue to function and ATP is not produced by aerobic respiration.

Also read: Important Topic: Plasmolysis

FAQs

What are the different levels of enzymes based on their function?

Based on their function, enzymes can be divided into six types. These types are as follows: Oxidoreductases, Transferases, Hydrolases, Lyases, Ligases, and Isomerases. Oxidoreductases activate oxidation-reduction by facilitating the transfer of electrons. The electrons transmitted are usually hydrogen atoms or ion hydrides. Transfers, on the other hand, enzymes simplify group transfer processes where a molecule is a donor while another molecule acts as a receptor.

How does the lactose molecule represent the key and pathway to enzymes?

The lactose molecule binds only to the lactase enzyme as it has a binding substrate specific to that substrate and is called an active site. When a substrate binds to an enzyme, a reaction occurs when the old bonds disintegrate and the formation of new bonds occurs thus forming a new molecule. The new molecule is a product and is made possible by locking and the main pathway of enzymes.