Fatty acid synthesis requires 14 NADPH molecules per palmitate formed. Besides the pentose phosphate pathway, which hepatic enzyme provides a substantial share of this NADPH?
- A NADP-dependent malic enzyme ✓
- B Glucose-6-phosphatase
- C Pyruvate carboxylase
- D ATP citrate lyase
Correct answer: A. NADP-dependent malic enzyme
Explanation
In the cytosol, oxaloacetate generated by ATP citrate lyase is reduced to malate by malate dehydrogenase using NADH, then oxidative decarboxylation of malate to pyruvate by NADP-dependent malic enzyme generates NADPH. Together with glucose-6-phosphate dehydrogenase of the pentose phosphate pathway, it supplies the reductant for fatty acid synthase. The other listed enzymes produce neither NADPH nor participate in this shuttle.
Reference: Harper's Illustrated Biochemistry, 32nd ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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