Definition, Functions and Types of Enzymes

About Enzyme

An enzyme is a biocatalyst synthesizes by a living cell.

An enzyme is a protein in nature except for RNA because of RNA act as a Ribo Enzyme.

An enzyme is a substance having thermolabile in character and colloidal in nature.

It posses the specific action for the substance.

Functions of Enzymes

  • All enzyme is protein in nature, the only exception is RNA is also capable of the enzymatic activity.
  • Each and every enzyme have an own specific confirmation and structure and these quality are very important for the enzymatic activity.
  • Some enzyme is required additional compound for the enzymatic activity is known as co-factor and co-enzyme.Co-factor:
    Co-factor is the substance consisted of the one or more than one inorganic ion.e.g. – iron, magnesium, zinc, etc. Co-enzyme:
    Co-enzyme consist a complex organic or metal organic molecule.e.g. – biocytine and co-enzyme A (CoA).
  • Some of the enzymes required no chemical substance for the catalytic activity.
  • Some of the enzymes are required both co-enzyme and a metal ion.
  • For the completion of the catalytic activity enzyme bound with the co-enzyme or co-factor is known as Holoenzyme. Holoenzyme = apoenzyme + co-enzyme/co-factor.

Types of Enzymes

Enzymes are classified in following types…

  1. Oxireductase
  2. Transferase
  3. Hydrolases
  4. Lyases
  5. Isomarase
  6. Ligase


This type of reaction is important for the transfer for the electron, hydroxide ions.
It posses the oxidation and reduction reactions.

e.g.- alcohol dehydrates.


This type of enzymatic reaction is important for the catalyzed group transfer reaction such as glycoside, methyl phasphoryle.

e.g.- Hexokinase.


It catalysed hydrolysis reaction. It transfer the functional group of H2O.

e.g.- lipase.


It forms double bond by removal of group.

e.g.- Aldolase.


Transfer of group within the molecule. This type of reaction also catalyzed the geometric or structure change within the molecule.

e.g.- triose phosphate isomarese.


This type of reaction catalysed C-C, C-S, C-O, C-N bonds. Its works with the help of condensation reaction.

e.g.- glutamine synthatases.

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Ankita Rai
Hey, I'm graduated in Pharmacy and working with a top reputed company as quality control and analysis. I love to share my ideas, and knowledge with everyone by writing articles on the latest pharmacy trends and thanks to Websparrow team to provide me a platform. Read all published posts by Ankita Rai.