Question
A 28-year-old male presents with sudden onset fatigue, jaundice, and dark urine 2 days after taking an antibiotic for fever. Labs show anemia, indirect bilirubin ↑, LDH ↑, reticulocytosis, and negative Coombs test. G6PD deficiency is suspected. Features of HMP shunt are:
| A. |
It does not produce ATP
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| B. |
Requires glucose 6 phosphate, G6P and NADH
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| C. |
Transketolase requires thiamine (TPP) as a cofactor
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| D. |
Both A & C
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Show Answer
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Correct Answer � D
Explanation
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– A. It does not produce ATP:
The hexose monophosphate (HMP) shunt (pentose phosphate pathway) mainly makes NADPH & ribose-5-phosphate, not ATP. It’s not an energy- producing pathway.
– C. Transketolase requires thiamine (TPP):
Transketolase acts in the non-oxidative phase & needs thiamine pyrophosphate (TPP) as cofactor.
Thiamine deficiency impairs this enzyme.
Reasons to rule out others:
– B. Requires glucose 6 phosphate & NADH:
It requires glucose-6-phosphate & NADP⁺, not NADH.
NADP⁺ is reduced to NADPH during the oxidative phase.
This cofactor error makes option B incorrect.
