Question

The role of NAD in the citric acid cycle is the same as it was in glycolysis; namely, to 'harvest' or 'extract the energy from glucose. What additional molecule helps with this process in the citric acid cycle? What, specifically, is being harvested by NAD and this other molecule?"

Answer 1

NAD and FAD are molecules that help extract energy from glucose in the citric acid cycle. They are reduced forms of NADH and FADH2, which are electron carriers storing the harvested energy. This energy is later used in the electron transport chain to generate ATP.

Step-by-step explanation:

In the citric acid cycle, NAD (nicotinamide adenine dinucleotide) plays a crucial role in extracting energy from glucose. However, in addition to NAD, another molecule called FAD (flavin adenine dinucleotide) also helps with this process. Both NAD and FAD are electron carriers that pick up high-energy electrons produced during the citric acid cycle.

Specifically, NAD and FAD are reduced to NADH and FADH2, respectively, by accepting these high-energy electrons. The energy harvested from glucose is stored in these reduced forms of NAD and FAD. These molecules, along with the electrons they carry, will later be used in the electron transport chain to generate ATP.