regulation
Last reviewed 01/2018
The electron transport chain and oxidative phosphorylation are closely linked. All of the enzyme complexes are near-equilibrium. Consequently, the rate of ATP production, or conversely the rate of NADH or FADH2 production from ATP, is dependent on the concentration gradient from substrate to product. Hence, increased activity of the tricarboxylic acid cycle in response to low cellular energy reserves will simultaneously increase the rate of activity of the electron transfer chain and oxidative phosphorylation.