|A) peptidase||B) amylase|
|C) lipase||D) thrombokinase|
The clotting of blood is a chain reaction initiated by the enzyme thrombokinase produced by the platelets. This causes prothrombin to be converted into thrombin in the presence of ion. Thrombin combines with fibrinogen to produce fibrin threads which entangles the corpuscles to form the clot.