The isocitrate is then transformed into alpha key to gluterate by the activity of isocytrade dehydrogenase. Now, if we want to produce more ATP molecules, we want to increase the rate of the citric acid cycle. So ATP produces a positive feedback loop that essentially increases the activity of this isoctrade dehydrogenase enzyme. But if we have plenty of ATP inside our body, the cell must signal somehow for the citric acid cycle to actually decrease its activity. In fact, it also has to signal for glycolysis to actually decrease its activity. And so what happens is ACP and NADH act as allosteric inhibitors.