Respiratory control links mitochondrial oxygen consumption to demand for ATP. When ADP permits faster ATP synthase turnover, proton return lowers the opposing electrochemical gradient, permitting faster Electron transport.[ref]
Molecular Biology of the Cell, 4th edition by Bruce Alberts and others. Chapter 14, Electron-Transport Chains and Their Proton Pumps, Respiratory Control Normally Restrains Electron Flow Through the Chain
The mitochondrial oxygen electrode assay tests this connection by changing ADP availability while observing oxygen. A slowed reaction rate alone cannot locate the cause: depleted substrate, scarce oxygen, impaired enzymes and a strong opposing electrochemical gradient can all restrict turnover. A renewed response to ADP helps distinguish these possibilities.
New to topics? Read the docs here!