Enzymes are essential organic substances that accelerate the rate of biochemical reactions occurring in living organisms. But there are some substances present in living beings that decrease the rate of biochemical reactions. Such substances are known as inhibitors. The inhibitor may be organic or inorganic in nature.
There are three broad categories of enzyme inhibition –
- Reversible inhibition.
- Irreversible inhibition.
- Allosteric inhibition.
The inhibitor binds non-covalently with enzyme and the enzyme inhibition can be reversed if the inhibition is further sub-divided.
The inhibitor is closely resemble with the real substrate. They are called substrate analogue.
The inhibitor binds at a site other the active site on the enzyme surface. This bindings impairs the enzyme function. The inhibitor has no structural resemblance with the substrate.
The inhibitors binds covalently with the enzymes and inactivate them, which is irreversible. These inhibitors are usually toxic poisonous substances.
Some of the enzyme possess additional sites, known as allosteric sites besides the active site. Such enzymes are known as allosteric enzymes. The allosteric sites are unique places on the enzyme molecule.