In IgG, the antigen binding site is formed by
A) the variable segment of the light chain.
B) the variable segment of the heavy chain.
C) the constant segment of the heavy chain.
D) the variable segment of the light chain + the variable segment of the heavy chain.
E) the variable segment of the light chain + the constant segment of the heavy chain.

Question

Quizplus · Accepted Answer

The antigen binding site in IgG is formed by the variable segments of both the light and heavy chains. These variable segments combine to create a unique binding site that recognizes and binds to a specific antigen. The constant segment of the heavy chain is responsible for the effector functions of IgG, such as complement fixation and antibody-dependent cell-mediated cytotoxicity, but it does not directly contribute to the antigen binding site.

In IgG, the Antigen Binding Site Is Formed by