A common intermediate in the conversion of glycerol and lactate to glucose is which one of the following?: (A) Pyruvate, (B) Oxaloacetate, (C) Malate, (D) Glucose-6-phosphate
Answer is D. The only intermediate included in the list that the pathway of gluconeogenesis from glycerol has in common with the pathway of gluconeogenesis from lactate is glucose-6-phosphate. Glycerol enters gluconeogenesis as DHAP. Therefore, it bypasses the other compounds (pyruvate, oxaloacetate, malate, and PEP) through which the carbons of lactate must pass on its pathway to glucose synthesis.