The function of vitamin K largely depends on which mineral ?

Ans. is 'b' i.e., Calcium Vitamin K plays an impoant role in blood coagulation for it is required for the post-translational processing of several clotting factors (factor II, VII, IX and X). Maturation of these clotting factors requires the conversion of glutamyl residues of precursor proteins into 'ycarboxyglutamate (Gla) residues by addition of carboxylate group. This carboxylation of glutamyl resdiue is vitamin K dependent. The y-carboxyglutamate (Gla) residues so formed serve as binding site for calcium ions. Each Gla contains two negative charges which chelate the positive calcium ion. After binding to Gla residue on activated clotting factor, calcium binds with negatively charged phospholipids present on the platelet cell membrane. In this way, bridging of the phospholipids the Gla residue of prothromin occurs calcium ion.