Inhibitors block the active site temporarily or permanently.
• Examples: poisons like cyanide, antibodies, anti-metabolites, pesticides and some drugs.
Types of Enzyme Inhibitors: The inhibitors can be divided into two types.
(i) Irreversible inhibitors
(ii) Reversible inhibitors
(i) Irreversible inhibitors:
They check the rate of reactions by occupying (d) the active sites or destroying () the structure.
They occupy the active sites by forming covalent bonds or they may physically block the active sites.
(ii) Reversible Inhibitors:
They form weak linkage () with the enzyme.
⚫ Their effect can be neutralized (4) completely or partly by an increase in the concentration of
the substrate. Reversible inhibitors are divided into two major types:
(a) Competitive inhibitor
(b) Non-competitive inhibitor