Question

Which of the following best explains the difference between epitope and an antigen?

• A. An epitope is any foreign substance , an antigen is a foreign protein.
• B. An epitope is part of an antigen where antibody or lymphocyte receptor binds.
• C. An antigen is the part of an epitope where antibody or lymphocyte receptor binds.
• D. Antigens are recognised by B-cells and antibodies, epitope are recognised by T-cells.

Answer 1

Answer: (B)

An epitope is part of an antigen where antibody or lymphocyte receptor binds.

• An epitope, also known as an antigenic determinant, is the part of an antigen that is recognized by the immune system, specifically by antibodies, B cells, or T cells. For example, the epitope is the specific piece of the antigen to which an antibody binds.
• The term antigen originally described a structural molecule that binds specifically to an antibody or lymphocyte only in the form of native antigen.
• Hence, An epitope is part of an antigen whereas antigen binds the antibody or lymphocyte receptor is the best explanation to the difference between epitope and an antigen.
• So, the correct answer is 'An epitope is part of an antigen where antibody or lymphocyte receptor binds.