Immunoglobulins consist of two identical heavy chains and two identical light chains. Both the heavy and light chains have constant (C) and variable (V) regions. The heavy chains are glycosylated, and the light chains are not. The hinge region confers flexibility to the molecule and allows it to accommodate antigen. There are intrachain disulfide bonds within the heavy and light chains and interchain disulfide bonds between the heavy and light chains.