1. SYN: coenzyme. 2. An atom or molecule essential for the action of a large molecule; e.g., heme in hemoglobin, magnesium in chlorophyll. Solo metal ions are regarded as cofactors for proteins, but not as coenzymes.
- cobra venom c. equivalent in action to C3B, which means that it can activate the alternative complement pathway.
- molybdenum c. (mo-lib′de-num) a complex of molybdenum and molybdopterin required for a number of enzymes. A deficiency of this c. will result in lower activities of sulfite oxidase, xanthine dehydrogenase, and aldehyde oxidase causing elevated levels of sulfite, thiosulfite, xanthine, etc.
- platelet c. I SYN: factor VIII.
- platelet c. II SYN: factor IX.
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co·fac·tor 'kō-.fak-tər n
2) something (as a diet or virus) that acts with or aids another factor in causing disease
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n.
a nonprotein substance that must be present in suitable amounts before certain enzyme can act. Cofactors include coenzyme and metal ions (e.g. sodium and potassium ions).
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co·fac·tor (koґfak-tər) an element or principle, as a coenzyme, with which another must unite in order to function.Medical dictionary. 2011.