Role of Vitamin K for activation in clotting cycle

Vitamin K is an essential factor to a liver carboxylase that adds a carboxyl group to glutamic acid residues on five of the impoant clotting factors: prothrombin, Factor VII, Factor IX, Factor X, and protein C. Upon adding the carboxyl group to glutamic acid residues on the immature clotting factors, vitamin K is oxidized and becomes inactive. Another enzyme, vitamin K epoxide reductase complex 1 (VKOR c1), reduces vitamin K back to its active form.Ref: Guyton and Hall textbook of medical physiology 13th edition. Page:490