Energy of nutrients

This reaction illustrates the use of chemical energy originally produced by the oxidation of nutrients and ultimately trapped by phosphorylation of ADP to ATP. Recall from Section 15.10 that ATP does not represent stored energy, just as an electric current does not represent stored energy. The chemical energy of nutrients is released by oxidation and is made available for immediate use on demand by being trapped as ATP. 

Interconversion of pyruvate and oxaloacetate. The formation of oxaloacetate is important because it is the starting point of the tricarboxylic acid cycle (TCA), known also as the KreErs cycle, in which the potential energy of nutrients (ATP) is releeised for use by the E)ody. 

---