Question

what important role does the bivalency of an Ig molecule play in immunity ?

Answer 1

Some antibodies are monovalent,some are bivalent and some are multivalent.The antigen-antibody reactions,or binding of an antigen to an antibody depends on certain factors,one of which is affinity,and avidity.The strength by which an antibody binds to a single antigen at its epitope is called affinity.In bivalent antibodies,there are two antigen binding sites,so the collective strength of binding different antigens at these sites is known as avidity.So,more the avidity,more strong and specific will be the binding.The reactions between bivalent antibodies and antigens are more stable than monovalent antibody and antigen.