Prothrombin is the coagulation factor that is required for the ordinary thickening of blood. A course of biochemical occasions prompts the arrangement of the last coagulation. In this course, prothrombin is a forerunner to thrombin. Thrombin (EC 3.4.21.5, fibrinogenase, thrombase, thrombofort, topical, thrombin-C, tropostasin, initiated blood-coagulation factor II, blood-coagulation factor IIa, factor IIa, E thrombin, beta-thrombin, gamma-thrombin) is a serine protease, a catalyst that, in people, is encoded by the F2 gene. Prothrombin (coagulation factor II) is proteolytically cut to frame thrombin in the thickening procedure. Thrombin thus goes about as a serine protease that changes over solvent fibrinogen into insoluble strands of fibrin, just as catalyzing numerous other coagulation-related responses.