Tag: blood clotting

The liquid part of coagulated blood is known as serum. It is the liquid portion of blood clot . It includes all proteins not used in clotting of blood and all the electrolytes, hormones, antibodies, antigens etc..

Blood coagulation is a complex biochemical process involving platelets and many proteins (enzymes).  Calcium is involved at several steps in the blood clotting, including the activation of the platelets, activation of clotting factors and enzymes which are present in the blood in inactive form. The $Ca^{++}$ ions bind with prothrombin and covert it into active form thrombin. The thrombin in turn converts fibrinogen into fibrin (a thread like protein) which traps red blood cells and helps in the formation of clot.

Sodium oxalate, like citrates, can be used to remove calcium ions (Ca${^2}$${^+}$) from blood plasma. It thus prevents blood from clotting. In the presence of calcium ions and other clotting factors, factor X activates an enzyme called prothrombin activator. This enzyme then converts the plasma protein prothrombin into thrombin. Thrombin is an enzyme that, in turn, converts fibrinogen to fibrin.