Citric acid cycle citrate synthase, control

How is control exerted within the citric acid cycle Within the citric acid cycle, the three control points are the reactions catalyzed by citrate synthase, isocitrate dehydrogenase, and the a-ketoglutarate dehydrogenase complex. 

The overall rate of the citric acid cycle is controlled by the rate of conversion of pyruvate to acetyl-CoA and by the flux through citrate synthase, isocitrate dehydrogenase, and a-lcetoglutarate dehydrogenase. These fluxes are largely determined by the concentrations of substrates and products the end products ATP and NADH are inhibitory, and the substrates NAD+ and ADP are stimulatory. 

On the basis of these observations, suggest how succinyl-CoA regulates the activity of citrate synthase. (Hint See Fig. 6-29.) Why is succinyl-CoA an appropriate signal for regulation of the citric acid cycle How does the regulation of citrate synthase control the rate of cellular respiration in pig heart tissue ... 

Within the citric acid cycle itself, the three control points are the reactions catalyzed by citrate synthase, isocitrate dehydrogenase, and the a-ketoglutarate dehydrogenase complex. We have already mentioned that the first reaction of the cycle is one in which regulatory control appears, as is to be expected in the first reaction of any pathway. Gitrate synthase is an allosteric enzyme inhibited by ATP, NADH, succinyl-GoA, and its own product, citrate. 

---