<prompt> Zinc is a cofactor ofAlcohol dehydrogenasePyruvate CarboxylasePyruvate oxidaseNone of the above  <response>: Metalloenzymes: These enzymes hold the metals rather tightly which are not readily exchanged. Alcohol dehydrogenase, carbonic anhydrase, alkaline phosphatase, carboxypeptidase and aldolase contain zinc.Phenol oxidase copper; Pyruvate oxidase manganese; Xanthine oxidase molybdenum; Cytochrome oxidase iron and copper.Satyanrayana, Ed 3, page no 91 