Quick Review Cards for Medical Laboratory Science

Functional Classification of

Coagulation Factors

Hematology Review 347

EXPLANATION FACTORS

Substrate Substance changed by an enzyme. Fibrinogen

Cofactor Protein that accelerates enzymatic reactions. No enzymatic V, VIII (V is cofactor for Xa; VIII is cofactor for IXa)

activity of its own.

Enzyme Protein that catalyzes a change in specific substrate. Serine proteases: thrombin (IIa), VIIa, IXa, Xa, XIa,

Secreted in inactive form (proenzyme, zymogen). Must be XIIa, prekallikrein

activated to function.

Transglutaminase: XIIIa

Letter “a” following Roman numeral indicates activated form of enzyme.