NUTR 3210 Lecture 7: VitKCaPF
26 Mar 2017
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Document Summary
Discovered by dam and doisy using chicks. Fed low-fat and cholesterol free diet bleed excessively. Produced by our gut bacteria (colonic microflora) as menaquinone. Injection if vit k in the heels of newborns. This supplies vit k until gut bacteria established. Present in green leafy plants as phylloquinone but get destroyed during cooking. Deficiency is very rare (sensitive to heat and light) Absorbed as is in the jejunum, no further breakdown. No specific site for storage, vit k is present in cell membranes of the lungs, kidneys, adrenal glands, bone, etc. Vitamin k quinone (a general term) converted to the active and reduced form, vitamin k. Vitamin k hydroquinone and co2 act as cofactor and work together with hydroquinone by the enzyme quinone reductase gamma-glutamyl carboxylase to convert the glutamate side chain on a protein precursor (e. g. pre-calcium binding protein) to gamma-carboxyglutamate side chain. This converts glutamic acid to gamma-carboxyglutamic acid.
