<P> Chemically, the vitamin K family comprises 2 - methyl - 1, 4 - naphthoquinone (3 -) derivatives . Vitamin K includes two natural vitamers: vitamin K and vitamin K. Vitamin K, in turn, consists of a number of related chemical subtypes, with differing lengths of carbon side chains made of isoprenoid groups of atoms . </P> <P> Vitamin K, also known as phylloquinone, is made by plants, and is found in highest amounts in green leafy vegetables because it is directly involved in photosynthesis . It may be thought of as the plant form of vitamin K. It is active as a vitamin in animals and performs the classic functions of vitamin K, including its activity in the production of blood - clotting proteins . Animals may also convert it to vitamin K . </P> <P> Bacteria in the gut flora can also convert K into vitamin K (menaquinone). In addition, bacteria typically lengthen the isoprenoid side chain of vitamin K to produce a range of vitamin K forms, most notably the MK - 7 to MK - 11 homologues of vitamin K. All forms of K other than MK - 4 can only be produced by bacteria, which use these forms in anaerobic respiration . The MK - 7 and other bacterially derived forms of vitamin K exhibit vitamin K activity in animals, but MK - 7's extra utility over MK - 4, if any, is unclear and is a matter of investigation . </P> <P> Because a synthetic form of vitamin K, vitamin K (menadione), may be toxic by interfering with the function of glutathione, it is no longer used to treat vitamin K deficiency . </P>

What organ contains bacteria that help produce vitamin k