Electrodynamic rather than Chemiosmotic theory of Oxidative Phosphorylation

The synthesis of ATP and the consumption of O 2 are usually determined in separate reactions in the presence of high levels of O 2 . Here, these two processes were simultaneously determined during the first 0.3 s of reactions initiated by adding in vivo levels of O 2 . We found the following novel aspects of oxidative phosphorylation. 1) The K M of isolated cytochrome aa 3 for O 2 is at least 50.0 μM. 2) The rates of ATP synthesis do not obey Michaelis‐Menten kinetics but vary exquisitely depending on the levels of ΔE h , O 2 and ADP. The higher the levels of ΔE h and O 2 the lower is the concentration of ADP required for half maximal rates of ATP synthesis. The higher the levels of ΔE h and ADP the lower is the affinity for O 2 and the higher the concentration of O 2 required for half maximal rates of ATP synthesis. 3) The rates of ATP synthesis and O 2 uptake are perfectly compatible with the extremely fast rates of electron flow and orders of magnitude higher than those observed under state‐3 conditions. 4) The rates of ATP synthesis are controlled more by the level of O 2 than by the level of ADP. 5) The ATP/O stoichiometry is not constant but varies between near zero and 3.4 depending on the levels of ΔE h , O 2 and ADP. 6) The actual synthesis of ATP from ADP and Pi can occur in the absolute absence of a proton gradient but never in the absence of O 2 and electron flow. It is postulated that the mechanism of ATP synthesis is electrodynamic rather than chemiosmotic