In this reaction, all reactants and products are invisible. The heat being evolved is the clue that tells you a reaction is taking place. This is a good example of an exothermic reaction, a reaction in which heat is given off. A lot of reactions are exothermic.
Prothrombinase will cleave prothrombin to make thrombin and thrombin is the enzyme that cuts fibrinogen to make fibrin for clot formation [Blood Clotting: The Basics]. The platelet prothrombinase activity is the same as the activity on TP-bearing cells: itâs formed from Xa and membrane-bound Va.
Prothrombin is the precursor of thrombin in the coagulation pathway; it is synthesized in the liver, much as other vitamin K â dependent proteins are, and has a molecular weight of 72 kd. The plasma half-life of prothrombin is approximately 60 hours. The reference range is between 70% and 120% of normal values. Next.