An enzyme that detoxifies hydrogen peroxide uses reduced glutathione as its electron donor, converting two GSH molecules to GSSG in the reaction. Deficiency of which trace element impairs this protective system and predisposes cardiomyocytes to oxidative injury?
- A Selenium ✓
- B Zinc
- C Molybdenum
- D Manganese
Correct answer: A. Selenium
Explanation
Glutathione peroxidase is a selenoenzyme; selenium sits in its active site as selenocysteine and is required to reduce hydrogen peroxide and lipid peroxides at the expense of reduced glutathione. Selenium deficiency therefore weakens antioxidant defense and is classically linked to Keshan disease, a cardiomyopathy in children of selenium-deficient regions of China. Zinc supports Cu/Zn superoxide dismutase but not this enzyme, manganese is the cofactor of mitochondrial superoxide dismutase, and molybdenum cofactors sulfite oxidase and xanthine oxidase.
Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.