Question

Antigen binding site in an antibody is found between

• A. Two light chains
• B. Two heavy chains
• C. One heavy and one light chain
• D. Both B and C depending upon nature of antigen

Answer 1

Answer: (C)

One heavy and one light chain

Antigen binding site, also known as paratope is a part of an antibody which recognizes and binds to an antigen. It is a small region of 5 to 10 amino acids of the antibody's Fv region, part of the fragment antigen-binding (Fab region), and contains parts of the antibody's heavy and light chains. Paratope is present in each arm of Y-shaped antibody between one heavy chain and one light chain.

So, the correct answer is 'One heavy and one light chain'.