Which is not a plasma protein?

correct Option is: A. Heparin

Solution:

• Plasma proteins refer to proteins present in plasma. It is composed of a mixture of simple proteins, conjugated proteins, and lipoprotein.
• There are three major plasma proteins in blood- Fibrinogen, globulin, and albumins. Hence, these are plasma proteins.
• Prothrombin (inactive state) is related to the coagulation of blood that transforms into active thrombin in case of injury. Thrombin converts fibrinogen to fibrin.
• Heparin is anti-coagulant that prevents the clotting of blood. Hence, it is not present in the plasma.

Hence, the correct answer is (A) Heparin.