Explain about the Component of Metalloenzymes?

Zinc is unique among the trace elements in that it is a part of enzymes for all six Enzyme Commission classes. As a component of these enzymes, it either provides structural integrity to the enzyme or participates directly in the reaction at the catalytic site. Zinc is a component of over 300 metalloenzymes and is therefore vital for many fundamental life processes. For example, as a component of carbonic anhydrase, it helps in rapid disposal of carbon dioxide; as a part of alcohol dchydrogenase, it is involved in the conversion of alcohol to aldehyde such as conversion of retinol to retinal.

It is also required for protein digestion since it's a component of carboxypeptidase A and aminoyeptidase, the enzymes involved in the digestion of smaller peptides released after the action of the proteolytic enzymes pepsin, trypsin and chymotrypsin. Superoxide dismutase which catalyzes the removal of superoxide radical requires two atoms of both zinc and copper. Zinc has a structural role in this enzyme. Delta amino levulinic acid dehydratase involved in haem synthesis also contains zinc. Similarly, DNA and RNA polymerase and deoxykinase involved in nucleic acid synthesis are zinc-dependent. Zinc also influences polysome conformation and is thus involved in protein biosynthesis.