Which two high-energy electron carriers are generated through the cycle's reactions?

The correct answer highlights the two high-energy electron carriers produced during the reactions of the citric acid cycle: NADH and FADH2.

NADH is formed when nicotinamide adenine dinucleotide (NAD+) accepts electrons during enzymatic reactions, specifically in steps where substrates are oxidized, such as the conversion of isocitrate to α-ketoglutarate and the conversion of malate to oxaloacetate. This process not only transfers electrons but also protons, contributing to the overall energy yield of the cycle.

FADH2 is generated through a similar process when flavin adenine dinucleotide (FAD) accepts electrons in reactions like the conversion of succinate to fumarate. Both of these carriers play critical roles by shuttling high-energy electrons to the electron transport chain, where they contribute to the production of ATP through oxidative phosphorylation.

In contrast, while ATP is indeed produced in the citric acid cycle, it is not regarded as a high-energy electron carrier in the same sense as NADH and FADH2. GTP can be generated in some organisms and can be converted to ATP, but it does not serve the primary role of an electron carrier. CoA is involved in