Final answer:
The conversion from fumarate to malate in the citric acid cycle does not result in the production of an NADH molecule. Three NADH molecules are produced in each turn of the cycle, but not during the fumarate to malate step.
Step-by-step explanation:
The conversion in the citric acid cycle that does not give rise to an NADH molecule is the conversion of fumarate to malate (option a). During this step, fumarase catalyzes the hydration of fumarate to malate, and no NADH is produced. On the other hand, the conversion from isocitrate to α-ketoglutarate (option b) involves isocitrate dehydrogenase, which reduces NAD+ to NADH.
The conversion from α-ketoglutarate to Succinyl-CoA (option d) involves α-ketoglutarate dehydrogenase, which also produces NADH. Lastly, the conversion of malate to oxaloacetate (option c) involves malate dehydrogenase, which reduces NAD+ to NADH.
There are three points in the citric acid cycle where NADH is formed: isocitrate to α-ketoglutarate, α-ketoglutarate to Succinyl-CoA, and malate to oxaloacetate. Therefore, three NADH molecules are produced on each turn of the cycle.