Question

where in the citric acid cycle does nadh regulate enzyme activity? citrate → isocitrate succinyl-coa → succinate fumarate → malate isocitrate → alpha-ketoglutarate i dont know yet

Explanation:

In the citric acid cycle, NADH regulates enzyme activity at the step of isocitrate → alpha - ketoglutarate. This is because NADH acts as an allosteric inhibitor of the enzyme isocitrate dehydrogenase, which catalyzes this reaction. High levels of NADH indicate that the cell has sufficient energy (as NADH is involved in ATP production through oxidative phosphorylation), so the enzyme is inhibited to slow down the citric acid cycle.

Answer:

Isocitrate → alpha - ketoglutarate