A molecle derived from two or more amino acids. In the human body they can be obtained by the partial digestion of proteins. Proteins are essential elements of all living cells. A site on the surface of a cell which in a lock and key fashion fits into a complementary site on another cell or protein, as in the binding of an antibody to an antigen . Involving the entire system or body.
Medications taken orally are systemic because they are distributed to the entire body.
A type of lymphocyte involved in cell mediated immunity that matures under the influence of the thymus. T cells destroy cells marked by antibodies or expressing specific antigens. Suppressor T cells diminish the immune response, helping to regulate it. The concentration of a substance in solution as determined by titration. Antibody concentrations are measured this way.