Biology - Human Health and Diseases Question with Solution | TestHub

An antibody molecule is composed of four polypeptide chains: two identical light chains and two identical heavy chains.

Each chain consists of a variable region at its N-terminal end and a constant region at its C-terminal end.

The variable regions of both the light and heavy chains come together to form the antigen binding site (paratope), which is highly specific for a particular antigen.

Therefore, the antigen binding site of the antibody is formed of the variable regions of both light and heavy chains.

Answer: variable regions of both light and heavy chains