<prompt> Selenium is essential for the:Glutathione peroxidaseGlutathione reductaseGlutathione synthetaseGlutathione hydroxylase  <response>: Ans. A. Glutathione peroxidasea. Glutathione peroxidase is a selenium containing enzyme which acts in synergism with vitamin E to protect against hydroperoxide free radical damage.b. First line of defense against hydroperoxide free radical damage is vitamin E tocopherol while the second line of defense is a selenium containing enzyme glutathione peroxidase. 