Electron Transport Chain Flashcards

Flashcards about Electron Transport Chain and Oxidative Phosphorylation

Oxidative Phosphorylation

A major source of ATP in aerobic organisms, taking place in the inner mitochondrial membrane.

Oxidative Phosphorylation

Generates 26 of the 30 molecules of ATP formed when one molecule of glucose is completely oxidized to CO2 and H2O.

Respiratory Chain

High-transfer potential electrons (NADH and FADH2) flow through a series of large protein complexes in the inner mitochondrial membrane, reducing oxygen to water.

Proton-motive force

Electron flow through complexes powers pumping of protons from inside mitochondria to outside, establishing a proton gradient.

ATP Synthase

Final phase of oxidative phosphorylation carried out by an ATP-synthesizing assembly driven by the flow of protons back into the mitochondrial matrix.

Proton Gradients

Converts free energy in biological systems.

Complex I (NADH: Ubiquinone oxidoreductase)

Transfers electrons from NADH to Coenzyme Q (Q).

Complex II (Succinate: Ubiquinone oxidoreductase)

Transfers electrons from FADH₂ to Coenzyme Q.

Coenzyme Q (Ubiquinone / Ubiquinol)

Mobile lipid-soluble electron carrier between Complex I & II and Complex III.

Complex III (Cytochrome c oxidoreductase)

Transfers electrons from Ubiquinol to Cytochrome c.

Cytochrome c

Mobile protein electron carrier transferring electrons from Complex III to IV.

Complex IV (Cytochrome c oxidase)

Transfers electrons from Cytochrome c to O₂.

ATP Synthase (Complex V)

Synthesizes ATP using proton gradient.

FMN

Oxidized form of flavin mononucleotide.

FMNH2

Reduced form of flavin mononucleotide

Ubiquinone (Q)

Oxidized form of Coenzyme Q.

Ubiquinol (QH2)

Reduced form of Coenzyme Q.

ATP Yield from NADH

NADH results in approximately 2.5 ATP molecules.

ATP Yield from FADH2

FADH₂ yields about 1.5 ATP molecules.

Glycerol 3-phosphate shuttle

Shuttle that transfers electrons from NADH to the mitochondrial electron-transport chain, reducing dihydroxyacetone phosphate to glycerol 3-phosphate.