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Mechanism

Cellular respiration / OXPHOS

Reference definition for a mitochondrial-biology node.

Core function

Definition

Category: Core function

Also known as: oxidative phosphorylation, electron transport chain, ETC

Oxidative phosphorylation (OXPHOS) is the core mitochondrial function: the electron transport chain (complexes I-IV) pumps protons to build a membrane potential that ATP synthase (complex V) uses to make ATP. Coenzyme Q10 is the mobile electron carrier between complexes I/II and III, which is why CoQ10 is discussed as an OXPHOS-adjacent compound.

Key points

  • OXPHOS supplies most cellular ATP; its efficiency and the integrity of the electron carriers decline in many aged and diseased tissues.
  • Coenzyme Q10 (ubiquinone) is an endogenous component of this chain, not an external drug target — supplementation is a repletion/antioxidant strategy, not a redesign of the chain.
  • Electron leak at the chain is the main physiological source of mitochondrial reactive oxygen species (see the mtROS page).

Related interventions

Sourcing

Standard bioenergetics reviews. Review-level description.

Reference synthesis (tier 4); verification: review_level_2026-07-12.