What is the process that produces most NADH contributing to ATP synthesis?

The citric acid cycle, also known as the Krebs cycle or TCA cycle, is the process that produces the majority of NADH during cellular respiration, which is essential for ATP synthesis. In this cycle, acetyl-CoA is oxidized, resulting in the reduction of NAD+ to NADH at several key steps. Each turn of the cycle generates three molecules of NADH, contributing significantly to the overall yield of reducing equivalents that will eventually be used in the electron transport chain to produce ATP.

NADH produced in the citric acid cycle serves as a crucial electron carrier, transporting electrons to the electron transport chain where oxidative phosphorylation occurs. This process harnesses the energy stored in NADH to generate ATP through oxidative phosphorylation.

Other processes like glycolysis produce some NADH, but the citric acid cycle leads to a higher yield. Fermentation also produces NADH, but it does not contribute to ATP synthesis in the same way because it occurs in anaerobic conditions and regenerates NAD+ without further ATP synthesis in the electron transport chain. Oxidative phosphorylation itself does not produce NADH; instead, it utilizes NADH produced earlier in the metabolic pathways. Thus, the citric acid cycle is indeed the primary source of NADH that drives