Question

Fill in the blank

Each arm of the Y-shaped antibody has identical ____________________ sites. The shape of these sites
must match the shape of the _______________________ on the antigen in order to bind.

Answer 1

Each arm of the Y-shaped antibody has identical epitope-binding sites. The shape of these sites must match the shape of the epitopes on the antigen in order to bind.

Step-by-step explanation:

The two arms of the Y-shaped antibody molecule are known as the Fab region, for "fragment of antigen binding." The shape of these sites must match the shape of the epitopes on the antigen in order to bind. The epitope specificity of the Fab regions is identical for each arm of a single antibody molecule, but varies between antibodies with different epitope specificities.