Unaltered final product of TCA cycle ?

TCA cycle consists of sequential reactions. It begins with condensation of four carbon oxaloacetate molecule with 2 carbon acetyl CoA molecule to form six carbon citrate molecule. In subsequent reaction two carbon atoms are lost in the form of CO2 at two different reactions. A series of modifications occur in the remaining four carbon atoms to ultimately form oxaloacetate. Thus the last substrate (oxaloacetate) of one cycle is ready for use as a substrate in the next cycle. In this way, there is no net generation of OAA, or of any of the cycle intermediates.