Explanation

Immunoglobulin G (IgG) is the most abundant class of antibodies found in blood serum and lymph and active against bacteria, fungi, viruses and foreign particles. The basic structure of all Ig is same, i, e., made up of light and heavy polypeptide chains , still they behave differently in similar physiological system. IgG possesses four polypeptide chains linked by disulphide bonds.