Fig. . Structure of immunoglobulin Each chain ( L and H ) has two terminals. They are C - terminal (Carboxyl) and amino or N-terminal.
Each chain ( L and H ) has two regions. They have variable ( V ) region at one end and a much larger constant ( C ) region at the other end. Antibodies responding to different antigens have very different (V) regions but their (C) regions are the same in all antibodies. In each arm of the monomer antibody, the (V) regions of the heavy and light chains combines to form an antigen – binding site shaped to ‘fit’ a specific antigenic determinant.
Consequently each antibody monomer has two such antigen – binding regions. The (C) regions that forms the stem of the antibody monomer determine the antibody class and serve common functions in all antibodies. The functions of immunoglobulin are agglutination, precipitation, opsonisation, neutralization etc.,