Question

Write an essay on clotting of blood.

Answer 1

Blood exhibits coagulation or clotting in response to an injury. This is a mechanism to prevent excessive loss of blood from the body. A clot or coagulum formed mainly of a network of threads called fibrins in which dead and damaged formed elements of blood are trapped. Fibrin are formed by the conversion of inactive fibrinogens in the plasma by the enzyme thrombin. Thrombin, in turn, are formed from another inactive substance present in the plasma called prothrombin. An enzyme complex thrombokinase is required for the above reaction. This complex is formed by the series of linked enzyme reactions (cascade process) involving a number of factors present in the plasma in an inactive state. An injury stimulates the platelets in the blood to release certain factors which activate the mechanism of coagulation.