Catalase is a heme-containing antioxidant enzyme that protects cells by directly decomposing hydrogen peroxide to water and oxygen. Unlike glutathione peroxidase, catalase does not require a reducing substrate. Catalase is predominantly localized in which subcellular organelle?
- A Mitochondria
- B Peroxisomes ✓
- C Endoplasmic reticulum
- D Cytosol
Correct answer: B. Peroxisomes
Explanation
Catalase is predominantly localized in peroxisomes, where it rapidly decomposes hydrogen peroxide generated by peroxisomal oxidases. While some catalase is cytosolic, peroxisomes contain the highest concentration. Mitochondria rely primarily on glutathione peroxidase, not catalase, for H2O2 detoxification.
Reference: Harper's Illustrated Biochemistry, 32nd ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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