Fig. 2

State space representation of initial levels of α ketoglutarate versus the rate of formation and consumption of α ketoglutarate. The rate of consumption of α ketoglutarate is invariant of the initial α ketoglutarate levels. On the other hand, the rate of formation of α ketoglutarate varies as a function of the initial levels of α ketoglutarate and eventually attains any one of the two stable states. An initial relative α ketoglutarate level above 0.28 would eventually attain state S1. On the other hand, an initial relative α ketoglutarate level below 0.28 would eventually attain the state S2. Thus, S1 and S2 represent the two stable states of α ketoglutarate levels indicating bistability