Riboflavin (vitamin B2) deficiency causes angular stomatitis, cheilosis, and seborrheic dermatitis. Riboflavin is the precursor for two major coenzymes. A patient with riboflavin deficiency would have impaired function of which enzyme?
- A Pyruvate dehydrogenase
- B Transketolase
- C Glutathione reductase ✓
- D Methionine synthase
Correct answer: C. Glutathione reductase
Explanation
Riboflavin is the precursor of FAD and FMN. Glutathione reductase is an FAD-dependent enzyme critical for maintaining reduced glutathione levels. Its activity is measured clinically as a functional marker of riboflavin status. Pyruvate dehydrogenase and transketolase require thiamine pyrophosphate (C1). Methionine synthase requires cobalamin (C12), making these plausible distractors from other vitamin-dependent enzymes.
Reference: Harper's Illustrated Biochemistry, 32nd ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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