Cell biology and proposed mechanisms
Oxidative phosphorylation
Oxidative phosphorylation is the process by which mitochondria make most of a cell's ATP. The electron transport chain builds a proton gradient across the inner mitochondrial membrane, and the enzyme ATP synthase lets those protons back through, using the flow to attach a phosphate to ADP.
Also called OXPHOS, chemiosmosis, aerobic respiration
How it works
The term joins two halves. “Oxidative” refers to the oxidation of NADH and FADH₂ by the electron transport chain, ending with oxygen. “Phosphorylation” refers to adding a phosphate group to ADP to make ATP. The two are linked not chemically but physically, by the proton gradient — Peter Mitchell’s chemiosmotic hypothesis, for which he received the Nobel Prize in 1978. Oxidising one NADH yields roughly two and a half ATP.
The alternative route, substrate-level phosphorylation, happens in glycolysis and the citric acid cycle and yields far less. The citric acid cycle is sometimes mentioned in the same breath, but it feeds oxidative phosphorylation rather than being it.
An important false friend
The “oxidative” in oxidative phosphorylation has nothing to do with the “oxidative” in oxidative stress, and antioxidants do not slow it down. One is a controlled, enzyme-guided transfer of electrons that generates energy; the other is uncontrolled damage by escaped reactive species. The two are easy to run together.
Where it fits with the equipment
Oxidative phosphorylation is the process that red and near-infrared photobiomodulation is proposed to accelerate, by acting on complex IV. It is not something ozone is proposed to act on directly.
Why it matters here
This is where the ATP story for red and near infrared light finally lands. It is also the clearest example of one word — oxidative — meaning two completely different things in the same conversation.