<prompt> Post translation carboxylation of clotting factors requires -Vitamin CVitamin KVitamin AVitamin D  <response>: Ans. is b i.e., Vitamin Ko The only known biological role of vitamin K is as a cofactor for an enzyme carboxylase that catalyzes carboxylation of glutamic acid glutamate Q residues on vitamin K-dependent proteins. The important vitamin K dependent proteins are : i Coagulation proteins: - Factor IIQ prothrombin, factor VII proconvertin0, factor IX Christmas factor, and factor XQ Stuart-Prower factor,ii Anticoagulation proteins: - Proteins S and Z.iii Gas 6 