An antibody is a protein created by the immune system in response to exposure to an antigen. When you are exposeed to an antigen, which is usually a protein from outside the body, the B lymphocyte cells (a type of white blood cell) create antibodies, which are proteins specially designed to combine with and bond to the antigen. The purpose of this bonding is to help the body inactivate the antigen, which may be associated with a bacteria or virus which can cause illness. Vaccines cause your body to develop antigens so that you will not catch an illness, or at least will get a much milder case, if you are exposed to it.
Newborn babies get antibodies from their mother's body and from her breast milk, which keeps them safe from various infections until their own immune systems begin to function after birth.
Proteins created by immune system in response to an antigen (toxin or bacterium) and helps fight against it. It is also called immunoglobulin.
Antibodies are the antigen binding proteis present on the B-cell membrane and secreted by
plasma cells. Membrane-bound antibody confers
antigenic specificity on B cells; antigen-specific proliferation
of B-cell clones is elicted by the interaction of
membrane antibody with antigen. Secreted antibodies circulate
in the blood, where they serve as the effectors of humoral
immunity by searching out and neutralizing antigens
or marking them for elimination.All antibodies share structural
features, bind to antigen, and participate in a limited
number of effector functions.