Question

Describe the structure of an antibody.

Answer 1

Antibodies are glycoproteins which are highly specific to antigens. They are also known as immunoglobulins (Igs). They have a 'Y' shaped structure. It consists of four polypeptide chains, two heavy (H) chains and two light (L) chains. The four polypeptide chains are held together by disulfide bonds to form a 'Y' shaped structure. The region holding arms and stem of antibody is termed as hinge. Each chain of the antibody includes two distinct regions, the variable region and the constant region. Variable regions constitute the antigen-binding site (paratope). This part of antibody recognizes and binds to the specific antigen forming an antigen-antibody complex.