An Epitope Associates with Which Part of an Antigen Receptor

Question

An epitope associates with which part of an antigen receptor or antibody?
A) the disulfide bridge
B) the heavy-chain constant regions only
C) variable regions of a heavy chain and light chain combined
D) the light-chain constant regions only
E) the tail

Accepted Answer

An epitope is a small region of an antigen that can be recognized and bound by a specific antigen receptor or antibody. This binding occurs between the variable regions of a heavy chain and a light chain combined in the case of antibodies, or the variable region of the antigen receptor of T or B cells. Thus, the correct answer is C.