Question

Vitamin K is required for
A. Change of Prothrombin to thrombin
B. Synthesis of Prothrombin
C. Change of Fibrinogen to Fibrin
D. Formation of thromboplastin

Answer 1

Hint: A nutrient that the body requires to remain healthy is vitamin K. Vitamin K acts as a coenzyme for vitamin K-dependent carboxylase, an enzyme necessary for the synthesis and other diverse physiological functions of proteins involved in hemostasis (blood clotting) and bone metabolism. It is very important to get approximately the same amount of vitamin K per day if you take a blood thinner such as warfarin.

Complete answer:
The blood clotting process requires the involvement of calcium and other clotting factors. An enzyme called the prothrombin activator is activated by Factor X. The prothrombin activator enzyme then transforms prothrombin plasma protein into thrombin. The enzyme that in turn transforms fibrinogen into fibrin is thrombin. At the wound site, polymerized fibrin along with platelets forms a clot. A plasma protein that is synthesised in the liver is prothrombin. To synthesise prothrombin, vitamin K is essential. So, 'synthesis of prothrombin' is correct.

Additional information: Inside the body, vitamin K builds proteins that can induce clotting if a patient takes warfarin. In comparison, vitamin K and warfarin function in different directions, where vitamin K increases the risk of blood clots, while warfarin acts to reduce these chances.
Hence option ‘B: Synthesis of Prothrombin’ is the correct answer.

Note: Vitamin K refers to fat-soluble vitamins present in foods that are structurally similar and are sold as dietary supplements. By producing proteins for healthy bones and tissues, vitamin K protects your body. For blood clotting, it also makes proteins. You may bleed too much if you do not have enough vitamin K. There's very little vitamin K in newborns.