Which antioxidant enzyme specifically reduces hydrogen peroxide to water using reduced glutathione (GSH) as the electron donor, and is particularly important in protecting against lipid peroxidation in cell membranes?

• A Superoxide dismutase
• B Catalase
• C Cytochrome c oxidase
• D Glutathione peroxidase ✓

Explanation

Glutathione peroxidase reduces H2O2 and lipid hydroperoxides to water and alcohols respectively, using GSH as the electron donor. This is critical for protecting membranes from lipid peroxidation. Superoxide dismutase converts superoxide to H2O2. Catalase also breaks down H2O2 but does not use GSH and is mainly peroxisomal.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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