Antigens Vs Antibody

 Hello everyone,

Staph has already  given a brief introduction to Immunology .

The following section describes some information of antigen and antibodies

An antigen  are  any substance foreign to the body that evokes an immune response . An antigen may be a foreign substance from the environment, such as chemicals, bacteria, viruses, or pollen. An antigen may also be formed inside the body, as with bacterial toxins  or tissue cells.

When an antigen (Ag) enters the body, the immune system produces antibodies (Ab) against it. It is like a battle with the army (Ab) fighting off invader (Ag). the Ab destroy the antigen which is then engulfed and digested by macrophages  , hence immune response winds down.

Each antibody has unique target known as antigen present on invading organisms. Since antigen can have multiple different binding site for Ab, a number of antibodies can bind. when 2 or more antigen binding sites are identical, an Ab can form a stronger bond with Ag.

Each antibody consists of four polypeptides - 2 heavy chains and 2 light chains joined to form a Y shaped molecule.

-Dixy