Question

How are prosthetic groups different from co-factors?

Answer 1

Enzymes are composed of one or several polypeptide chains. But in many cases, non-protein constituents called co-factors are bound to the enzyme. A co-factor makes the enzyme catalytically active. There are three types of co-factors, viz. prosthetic groups, co- enzymes and metal ions.

Prosthetic groups are different from other co-factors in the sense that they are tightly bound to the apoenzyme. For example; haem is the prosthetic group and it is a part of the active site of the enzyme.