Question

In an antibody molecule, the antigen-binding site is present on ____________.

Options

• Variable regions of heavy and light chains

• The region holding arms and stem

• Constant regions of heavy and light chains

• Constant region of light chains

Answer 1

In an antibody molecule, the antigen-binding site is present on Variable regions of heavy and light chains.

Explanation:

A disulphide bond formed in a Y shape holds two heavy and two light chains of polypeptide together. The fork's two arms each have a changeable end with one heavy and one light chain that serves as an antigen binding site.