zinc and copper

Zinc"Zn":
Zinc is found in biological systems only in the +2 valence state, so that biological
oxidation-reduction function is not possible with Zn.
The metabolic function of Zn are based on its
1. Presence as integral component of many metalo enzyme is the most important include,
carbonic anhydrase, alkaline phosphatase, DNA &RNA polymerases, thymidine kinase
Carboxy peptidase & alcohol dehydrogenase.
The Zn atom are an integral, firmly bonds and are often involved in the active site they
also contribute the confirmation and structural stability of many metalo enzymes.
2. Zn plays major role in protein synthesis & has an important
function in gene expression.
3. Zn has been shown to be an important element in wound healing by
affecting the biosynthesis &integrity of connective tissue.
Metabolism:
1.4-2.3 g present in 70 kg adult. Prostate, liver , semen , kidney , bone &muscles are
rich in Zn.
The Zn contain of erythrocyte is about 10 times that if plasma best of their rich content of carbonic anhydrase &other Zinc containing enzymes.
A proximal 20-30 % of ingested dieter Zn absorbed.
The absorption process is active, energy dependent & mediated by specific transport (binding) ligand.
High-protein foods such as meat, fish & diary products are good sources if available Zn- Diet rich in proteins stimulate Zn absorption, whereas diet low in proteins has the apposite effect.
The RDA for Zn is 15 mg/day for adult males. Zn is transported in plasma mostly by albumin 60-70 % & by macro globulin 30-40 % & small amount with transferrin & amino acids.