Explanation

Antigenic determinants or epitopes are those sites on antigens, which are recognized by antibodies and receptors present on T and B-cells. Each antigen determinant can stimulate the formation of a particular kind of antibody or cell. The antibody’s antigen binding sites are located on the variable portion of the antibody. These sites help antibodies to combine specifically with antigens in the manner of lock and key. Hence, antigen determinants differ from antigen binding sites by their location, function and structure also.