Lipid peroxidation chain reaction is initiated by reactive oxygen species. The chain-terminating antioxidant that donates a hydrogen atom to lipid peroxyl radicals and is regenerated by vitamin C is:

• A Glutathione
• B Beta-carotene
• C Vitamin E (alpha-tocopherol) ✓
• D Uric acid

Explanation

Vitamin E (alpha-tocopherol) is the primary lipid-soluble chain-breaking antioxidant. The tocopheroxyl radical formed after it donates a hydrogen to a lipid peroxyl radical (LOO•) is reduced back to tocopherol by ascorbate (vitamin C), which is then regenerated by glutathione via the glutathione peroxidase/reductase system. This network constitutes the antioxidant recycling cascade: Vit E → Vit C → GSH → NADPH (from HMP shunt). Glutathione primarily acts in the aqueous phase. Beta-carotene quenches singlet oxygen. Uric acid is a water-soluble antioxidant but does not participate in lipid peroxidation chain termination in membranes.

Reference: Harper's Illustrated Biochemistry, 32nd ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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