The metal ion present in vitamin B12 is : A)cobalt B)zinc C)nickel D)iron
Option A) The structure of B12 is based on a corrin ring, which is similar to the porphyrin ring found in heme, chlorophyll, and cytochrome. It contains the biochemically rare element cobalt sitting in the center of the ring. Also called cobalamin, it is a water-soluble vitamin
