Question

Antigenic determinants bind to which of the following portions of an antibody?

Options

• Variable regions

• Constant region

• Only light chains

• Only heavy chains

Answer 1

Variable regions

Explanation:

Antigenic determinants (epitopes) bind to the variable regions of an antibody. The variable regions, located at the tips of the antibody’s light and heavy chains, provide specific antigen-binding sites that recognize and attach to particular antigens. The constant region, on the other hand, mediates other immune functions but does not bind antigen directly. Both light and heavy chains contribute to the variable region structure, so binding is not exclusive to either chain alone.