Vit K is available as all except ?

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 5th/e - 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 Ca+2 and to get bound to phospholipids surfaces - propeies essential for paicipation in the coagulation cascade.