Oxidative Phosphorylation and the Electron-Transport Chain

These flashcards cover key vocabulary terms related to oxidative phosphorylation and the electron-transport chain.

Oxidative Phosphorylation

A metabolic pathway that captures energy from electrons to synthesize ATP via the electron-transport chain and ATP synthase.

Electron-Transport Chain (ETC)

A series of protein complexes in the inner mitochondrial membrane that transfer electrons from NADH and FADH2 to O2, generating a proton gradient.

Proton Gradient

A difference in proton concentration across a membrane created by electron transport, used to drive ATP synthesis.

Respiratory Chain

Another name for the electron-transport chain which consists of proton pumps and links to the citric acid cycle.

NADH-Q Oxidoreductase (Complex I)

The first protein complex in the electron-transport chain that receives electrons from NADH.

Succinate-Q Reductase (Complex II)

The second protein complex in the electron-transport chain that receives electrons from FADH2; not a proton pump.

Q-Cytochrome c Oxidoreductase (Complex III)

The third protein complex in the electron-transport chain that transfers electrons to cytochrome c.

Cytochrome c Oxidase (Complex IV)

The final protein complex in the electron-transport chain that reduces O2 to H2O.

Reactive Oxygen Species (ROS)

Highly reactive derivatives of oxygen formed during electron transport that can cause cellular damage.

Proton-Motive Force (Δp)

The combined chemical and electrical gradient generated by the proton gradient, driving ATP synthesis.

ATP Synthase

An enzyme complex that synthesizes ATP from ADP and inorganic phosphate, powered by the proton gradient.

Acceptor Control

The regulation of oxidative phosphorylation by the availability of ADP, which controls the rate of electron flow in the ETC.

Uncoupling Protein 1 (UCP-1)

A protein that allows protons to re-enter the mitochondria without generating ATP, producing heat instead.

Chemiosmosis

The process through which ATP is produced using the energy from the proton gradient created by the electron-transport chain.

Inhibition of Electron Transport Chain

Occurs when specific inhibitors prevent electron flow, thus blocking ATP production and the formation of the proton gradient.