How do enzymes catalyse a chemical reaction in the living system? Explain drug-target interaction taking the example of an enzyme as a target.

(N/A) Enzymes catalyze reactions by providing a binding site for the substrate. The substrate binds to the active site of the enzyme through various interactions such as ionic bonding,hydrogen bonding,van der Waals interactions,or dipole-dipole interactions. This binding lowers the activation energy of the reaction,thereby increasing the rate of the reaction.
Drug-target interaction: Drugs often act as enzyme inhibitors. They can interact with the active site of the enzyme in two ways:
$1$. Competitive Inhibition: The drug competes with the natural substrate for the active site of the enzyme. Since the drug is structurally similar to the substrate,it binds to the active site,preventing the substrate from binding.
$2$. Non-competitive (Allosteric) Inhibition: The drug binds to a different site on the enzyme,known as the allosteric site. This binding changes the shape of the active site,making it impossible for the substrate to bind effectively.