Question

Give an account of the generalised structure of an antibody molecule produced by B-lymphocytes in response to the pathogen.

Hint:

Antibodies are specific to antigens and made of two heavy and two light chains. HIV prevention includes awareness, safe sex, safe blood, and ART programs.

Answer 1

Step 1: An antibody is a Y-shaped glycoprotein made by B-lymphocytes in response to an antigen.
Step 2: Structure of an antibody molecule:

• Composed of four polypeptide chains — two identical light (L) chains and two identical heavy (H) chains.
• Chains are held together by disulfide bonds.
• Each chain has a variable region and a constant region.
• The variable region forms the antigen-binding site — specific to each antigen.
• The constant region determines the antibody class (IgA, IgG, etc.).

Step 3: The specificity of the antibody is due to the antigen-binding sites present on the variable regions of the light and heavy chains.