Question

Each antibody can bind ________.

A) two different types of epitopes
B) two epitopes of the same kind
C) three epitopes of the same kind
D) two epitopes of one kind and one epitope of a different kind
E) one epitope only

Answer 1

Each antibody can bind two epitopes, either identical or different, depending on their similarity and spatial arrangement on the antigen, determined by the unique amino acid patterns of the antibody's variable regions.

Step-by-step explanation:

Each antibody can bind two epitopes of the same kind. Antibodies recognize and interact not with entire antigens, but with smaller exposed regions on their surface known as epitopes. An antibody's specificity is determined by the unique pattern of amino acids within its variable regions, allowing it to bind to complementary molecular sequences on the epitope. Cross reactivity occurs when antibodies raised against one antigen also bind to different antigens with similar epitopes. However, typical antibodies have two antigen-binding sites, and therefore, each antibody can bind to either two identical or two different epitopes, depending on their similarity and spatial arrangement on the antigen.