In the context of the given picture, answer the following questions:
How many peptide chains are present in each antibody molecule?
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → 4
An antibody is a Y-shaped protein made of four peptide (polypeptide) chains. The chains are held together by disulphide (S–S) bonds. So an antibody is written as H2L2, which means two heavy and two light chains, four in all.
NCERT Extract:
Acquired Immunity – “… The B-lymphocytes produce an army of proteins in response to pathogens into our blood to fight with them. These proteins are called antibodies. The T-cells themselves do not secrete antibodies but help B cells to produce them. Each antibody molecule has four peptide chains, two small called light chains and two longer called heavy chains. Hence, an antibody is represented as H2L2.”