Enzyme

Enzyme

Enzymes are the biological catalyst that accelerates the rate of a biochemical reaction.

Enzymes and Proteins

When an enzyme is acted upon pepsin the crystalline composition of the enzyme disappears with the decrease in its catalytic activity.

Having a complex structure like proteins which are a unique complex molecule.

Heat, acid, alkali, and other agents that denature proteins also destroy the activity of enzymes.

Show color reaction and ultraviolet absorption spectrum which is a characteristic of a protein.

Enzymes, Hormones, Difference between enzyme and hormone.

Molecular Structure of Enzyme

There are two general types of structure of enzymes found. They are amphoteric and collided with nature.

Simple Protein Molecule

Containing only amino acids.

Conjugated Protein Enzyme

Having two parts

Apo Enzyme – Amino acids

Cofactor Enzyme – A non-protein molecule

The enzyme molecule containing protein and cofactor is known as the holoenzyme.

Cofactor may be an inorganic metal ion or an organic prosthetic group or coenzyme.

General Properties of an Enzyme

They are active in extremely small amounts.

The enzyme remains unaffected by the reaction.

The enzyme does not affect the equilibrium of the reaction.

They are specific in nature.

They are thermolabile in nature.

Nomenclature and Classification of Enzyme

An enzyme is divided into six major class:-

Oxidoreductase enzyme

Catalyze oxidoreductase reaction, e.g. cytochrome oxidase catalyzes the oxidation of cytochrome.

Transferase

Transfer the functional group other than hydrogen from one substance to another e.g, Glutamate pyruvate transaminase catalyzes the shifting of an amino group from glutamate to pyruvate.

Hydrolase

Catalyze the hydrogen of a substrate by adding constituents of the water e.g. esterase

Lyases

Catalyze the reaction in which substrate e.g, Histamine decarboxylase breaks the covalent bond between carbon atoms.

Isomerase

Catalyze the reaction in which substrate is converted into its positional or optical isomer by intermolecular rearrangement e.g. Phosphohexoisomerase catalyzes the conversion of glucose 6 phosphates into fructose.

Ligases

The enzyme catalyzes the linking together pyruvate and carbon dioxide to form oxaloacetate.