Answer
antigen-binding site, epitope
Work Step by Step
Part of an antibody called the antigen-binding site binds to part of an antigen called the epitope.
The basic structure of an antibody is two light chains and two heavy chains linked together. All four chains have a variable (V) region which not only gives an antibody its uniqueness but also serves as an antigen-binding site on each of the two antibody’s arms.
Epitopes are regions on an antigen molecule that stimulate immune responses.
