Definition of an antibody.
An antibody is chemical substance protein in nature produced by special white blood cells called lymphocytes in response to a certain antigen and are specific in nature. they form the second line defense in the immune system and are long lived.
Structure of the antibody.
The antibody is made up of polypeptide chains. There are three different polypeptide chains: the heavy chain, the light chain and the variable chain. The light and heavy chains are linked by disulfide bridges