Zinc associated with all organelles of the cell but only 60 to 80% of cellular zinc is localized in the cytosol; the remainder has been shown to specifically bound to membranes that may be important in defining the effects of zinc deficiency on cellular functions.
After zinc is absorbed in the small intestine, it combines with plasma proteins for transport to the tissue. Relatively large amounts of zinc are deposited in bones.
Zinc is a constituent of more than 200 metallo-enzymes, including carbonic anhydrase, alcohol dehydrogenase, superoxide dismutase, DNA-polymerase, RNA-polymerase, alkaline phosphatase, and carboxy-peptidases.
Thus zinc involved in the biosynthesis of nucleic acids, protein metabolism (synthesis and digestion), bone metabolism, oxygen transport dark adaptation, defense system, and many others.
As a transition element, Zinc has the ability to form stable complexes with side chains of proteins and nucleotides, with a specific affinity for thiol and hydroxyl groups and for ligands containing nitrogen; zinc generally forms complexes with a tetrahedral arrangement of ligands around the metal.
The zinc ion acts as a good electron acceptor, but does not participate in direct oxidation-reduction reactions.
The body of healthy human adults contains 2 to 3 g of zinc and requires around 15 mg of dietary zinc per day. The zinc concentration of muscles varies with their metabolic functions. The highest zinc concentrations are found in skeletal muscles that are highly oxidative.
Zinc metabolism in human body
