What are enzyme inhibitors? Classify them on the basis of their mode of attachment to the active site of enzymes. With the help of diagrams,explain how inhibitors inhibit enzymatic activity.

(N/A) Enzyme inhibitors are foreign substances that bind to the active site of an enzyme and inhibit its catalytic activity.
They are classified into two types based on their mode of attachment:
$1$. Competitive Inhibitors: These compete with the natural substrate for the active site of the enzyme. They resemble the substrate in molecular shape.
$2$. Non-competitive (Allosteric) Inhibitors: These bind to a site other than the active site of the enzyme,known as the allosteric site. This binding changes the shape of the active site so that the substrate cannot bind to it.
Diagrammatic explanation:
$(a)$ Competitive inhibition: The inhibitor occupies the active site,preventing the substrate from binding.
$(b)$ Non-competitive inhibition: The inhibitor binds to the allosteric site,causing a conformational change in the enzyme's active site,rendering it ineffective.