Question

Blood clotting is helped by
(a) ${ Na }^{ + }$
(b) ${ K }^{ + }$
(c) ${ Ca }^{ 2+ }$
(d) ${ Mg }^{ 2+ }$

Answer 1

Hint: Blood clotting occurs in our body when we suffer from an injury that results in bleeding. The process of blood clotting requires a mineral ion that can coagulate blood. The other ions mentioned cause inhibition of clotting.

Complete step by step answer:
Blood clotting or coagulation is a process that prevents excessive bleeding, blood loss, and death by forming a clot over the wound. This process involves the participation of platelets, ions, and proteins.
The process of clotting requires the presence of ${ Ca }^{ 2+ }$ ions and various proteins known as clotting factors. Calcium works with vitamin K as well. Chelation of ${ Ca }^{ 2+ }$ ions inhibits clotting.
The steps involved in blood clotting are activation, adhesion, and aggregation of platelets, and deposition and maturation of fibrin.
- Platelet aggregation and fibrin formation require thrombin, a proteolytic enzyme. This is a serine protease that is formed from the proteolytic cleavage of prothrombin. Thrombin converts fibrinogen in the plasma into fibrin which are threads that trap dead and damaged blood cells.
- The factors required for coagulation of blood are present in the plasma of the blood and this plasma without the clotting factors is known as serum.
- The body naturally dissolves a blood clot after an injury has healed. However, in some conditions, the clot does not dissolve and if this occurs inside a blood vessel, can be extremely fatal.
So, the correct answer is ‘(c) ${ Ca }^{ 2+ }$’.

Note:
- The factors necessary for blood clotting are present in the plasma. Fibrinogen is the major protein present. These proteins are in an inactive form and are activated on injury to the blood vessels.
- Platelets are also known as thrombocytes and they are produced from megakaryocytes present in the bone marrow.