non-protein components of enzymes whose activity would not exist without their presence. Cofactors are generally stable to heat whereas most enzyme proteins lose activity on heating. See enzymes. cosmaceuticals -- the term used to describe cosmetics containing ingredients that are bioactive, exerting effects on people. "High-performance" cosmetics where the active ingredients are bioactive and/or the formulation uses new delivery system technology. The name is derived from combining cosmetics and pharmaceuticals.

nonprotein molecules that assist enzymes.

1. Substances, microorganisms, or characteristics of individuals that may influence the progression of a disease or the likelihood of becoming ill. 2. A substance, such as a metallic ion or coenzyme, that must be associated with an enzyme for the enzyme to function. 3. A situation or activity that may increase a person's susceptibility to AIDS. Examples of cofactors are: other infections, drug and alcohol use, poor nutrition, genetic factors, and stress. In HIV immunology, the concept of cofactors is being expanded and new cofactors have been identified. A recent example is the discovery of the interaction of CXCR4 (fusin) and CD4 to facilitate entry of HIV into cells.

See cofactor.