Substance which binds to substrate other than catalytic enzyme is ?

Ans. is 'b' i.e., Non-competitive inhibitor Non-competitive inhibitor In this type of inhibition no competition occurs between substrate and inhibitor. Inhibitor is structurally different from substrate and binds to enzyme at a site other than the substrate binding (catalytic) site. Occupancy of this site by the inhibitor alters the shape of the enzyme such that its catalytic activity is reduced or lost. The substrate is still able to bind the enzyme, but the enzyme cannot catalyze the reaction when inhibitor is bound. Thus, the non-competitive inhibitor does not block the active site of enzyme, but behaves as though it were removing active enzyme from the solution. Evidently, unlike competitive inhibition, increasing the substrate concentration does not reverse the inhibition. Non-competitive inhibition may be reversible or irreversible.