An antibody monomer, for example in an IgG molecule, has four polypeptide chains , two light chains and two heavy chains. Each chain has a variable and a constant region.
Work Step by Step
The variable region recognizes and binds to the antibody's unique antigen. The constant region determines (decides on ) the mechanism that the antibody will use to mark the antigen ( foreign entity/substance) for destruction --neutralization, agglutination, precipitation or complement fixation..