Solution:
- 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.
- Four polypeptide chains are held together by disulfide bonds to form a ‘Y’ shaped structure.
- 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 the antibody recognizes and binds to the specific antigen forming an antigen-antibody complex.