But unlike CTP, when ATP binds onto these regulatory chains, it actually increases the rate of activity of this enzyme and increases the rate of activity of the enzyme by displacing the CTP molecule from that regulatory chain and shifting the entire curve from the T state to that R state. So Adamosine triphostate, or ATP, is also now a steric effector of atcase. It binds to the same side on the regulatory chain, but it actually increases the activity of that ATCA. So at high concentration of ATP, the ATP will displace the CTP from the regulatory side on those regulatory chains, and that will shift the equilibrium from the T state to the R state and make the active sites much more likely to actually bind and convert that substrate molecule into the final product, the CTP. Now, the question is, what is the physiological significance of this effect? Why exactly does a high concentration of ATP activate this enzyme in the first place?