Question

which of the following describes the antioxidant activity of selenium?
multiple choice
selenium is required for the activity of glutathione peroxidase, an enzyme that chemically converts peroxides into water
selenium reactivates vitamin e after vitamin e has neutralized a free radical
selenium is required for the activity of superoxide dismutase, an enzyme that chemically converts the highly reactive superoxide anion into oxygen and hydrogen peroxide
selenium donates electrons to free radicals in cell membranes

Explanation:

To determine the correct description of selenium's antioxidant activity, we analyze each option:

• Option 1: Selenium is a cofactor for glutathione peroxidase, which converts peroxides (harmful oxidants) to water, a key antioxidant function.
• Option 2: Selenium does not reactivate vitamin E; this is incorrect.
• Option 3: Superoxide dismutase (SOD) does not require selenium (some SODs use other metals like copper/zinc or manganese); this is incorrect.
• Option 4: Selenium does not directly donate electrons to free radicals in cell membranes; this is not its primary antioxidant mechanism.

So the correct option is the first one.

Answer:

A. Selenium is required for the activity of glutathione peroxidase, an enzyme that chemically converts peroxides into water