Match the class of compounds given in Column I with their functions given in Column II.

Answer

`Ararr(2) B.rarr(4) C.rarr(1) D.rarr(5) Erarr(3)`

Explanation

A. Antagonist drugs are used when blocking of message is required e.g., doparmine antagoist is a drug which blocks the dopamine receptors antagonism.
B. Agonist drugs are useful when there is lack of chemical messenger e.g., herion.
C. These chemical messengers are received at the binding sites of receptor. These communicate between two neurons and that between neurons to muscles.
D. Inhibitors block the binding site of the enzyme and prevent the binding of the substrate, or inhibitthe catalytic activity of the enzyme. ltbr E. Receptors are proteins that are crucial to body's communication. They are embedded in the cell membrane in such a way that their small part possessing active site projects out of the surfae of the membrane of and opens on the outside region of the cell membrane.