Question

Which of the following correctly explains an epitope?

• A.
  Region of antibody that binds with antigen
• B.
  V–region of e light chain of antibody
• C.
  Heavy chain of an antibody
• D.
  Region of antigen that elicit secretion of specific antibody

Answer 1

The correct option is D

Region of antigen that elicit secretion of specific antibody
Each tip of the “Y” of an antibody contains a paratope that is specific for one particular epitope (analogous to a lock and key) on an antigen, allowing these two structures to bind together with precision. The small site on an antigen to which a complementary antibody may specifically bind is called an epitope or antigenic determinant.

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.