Explain the structure of immunoglobulin with suitable diagram.

Explanation

An antibody molecule is Y shaped structure that comprises of four polypeptid chains,two identical light chains (L) of molecular weight 25,000 Da(approximately 214 amino acids) and two identical heavy chains(H) of molecular weight 50,000 Da (approximately 450 amino acids).The polypeptide chains and two heavy chains are attached to each other to form a Y shaped structure .Hence ,an antibody is represented by `H_(2)L_(2)`.The heavy chains have a flexible hinge region at their approximate middles.
Each chain (L and H) has two terminals They are C -terminal (carboxyl) and amino or N-teminal.Each chain (L and H) has two 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 .Conssequently each antibody monomer has two such antigen-binding regions.The (C ) regions that forms the stem of the antibody monomer determine the antibody class abd serve common functions in all antibodies.