Antibody

Antibody

antigen-binding proteins produced by B cells and released in blood and lymph

Five main classes

IgA, IgD, IgE, IgG and IgM

Structure

has a quanternary structure, consisting of two heavy polypeptide chains and two light polypeptide chains arragned in a Y shape, have two antigen binding sites at the top of the arms for the same specific complementary antigen

Chains have distinct regions

constant region does not vary between antibodies or the same class and variable region that differs between antibodies

Neutralisation

antibodies bind to the surface antigens on pathogens and block their receptors to inhibit them from infecting healthy body cells

Opsonisation

bind to the surface antigens on pathogens to from antigen-antibody complexes and tag pathogen for destruction

Agglutination

bind to the surface antigens on pathogens to form antigen-antibody complexes that cause pathogens to clump together and become more visable

precipitation

antibodies bind to soluble antigens, making them insoluble

inflammation

antibodies can trigger the release of histamine causing inflammation