The term feedback inhibition refers to a situation in which
the substances at the end of a long series of reactions inhibits a reaction
at the begining of the series of reactions. For example
In this chain of reactions substances A is convered to
substance B which is in turn converted to substance C.
Substance C then can be used in other
reactions. As long as substance C is used up the chain of reactions continue
When
substance C is not consumed then its concentration can build up. Under
these conditions substance C could bind to the allosteric site on the enzyme-1,
causing the enzyme to change shape and be unable to bind to substrate.
When
substance C again starts to be consumed then the inhibitor that bound
the enzyme will dissociate, and the enzyme will regain activity
back to Modulators
of enzyme activity