<prompt> Vit K is available as all except ?MenoquinoneMenadionePhytonadionePhytoquinone  <response>: Ans. is d i.e., Phytoquinone Vitamin-K It is a fat soluble vitamin. It is the major coagulant of human body coagulants are substances which promote coagulation. It is of three types ? a K1 from plants - Phytonadione b K2 Produced by bacteria - Menaquinones C K3 Synthetic - Menadione Half life of vit K is 72 hours - Mahenderbhan Singh 5the - 348 lit K acts as a cofactor at a late stage in the synthasis of coagulation factors by liver - Prothrombin factor II, Factor VII, IX and X also protein C Protein 8. It catalyzes the final step in activation of these factors i.e. gamma carboxylation of glutamate residues which confers on them the capacity to bind Ca2 and to get bound to phospholipids surfaces - propeies essential for paicipation in the coagulation cascade. 