Oxidative Phosphorylation Flashcards

Flashcards covering key vocabulary terms related to oxidative phosphorylation.

Oxidative Phosphorylation

Process of generating ATP from the oxidation of coenzymes NADH and FADH2

Pyruvate Dehydrogenase Complex

Enzyme complex that oxidizes pyruvate to form acetyl-CoA, linking glycolysis to the TCA cycle.

TCA Cycle (Krebs Cycle)

Series of enzymatic reactions in the mitochondrial matrix that oxidizes acetyl-CoA, producing NADH, FADH2, and GTP.

Mitochondrial Pyruvate Carrier (MPC)

Transports pyruvate across the inner mitochondrial membrane.

Malate-Aspartate Shuttle

Shuttle system used to transfer electrons from cytoplasmic NADH to mitochondrial NAD+ in tissues with low energy requirements.

Glycerol-Phosphate Shuttle

Shuttle system used to transfer electrons from cytoplasmic NADH to mitochondrial FAD in metabolically active tissues.

Ubiquinone (Coenzyme Q)

Molecule that accepts electrons from Complex I and Complex II of the electron transport chain.

Ubiquinol (QH2)

Reduced form of ubiquinone, which carries electrons to Complex III.

Electron Transport Chain (ETC)

Transmembrane protein complexes in the inner mitochondrial membrane that accept electrons from NADH and FADH2.

ΔG0’ for oxidation of NADH = -220 kJ/mol

Oxidation of NADH releases this amount of energy.

ΔG0’ for oxidation of FADH2 = -150 kJ/mol

Oxidation of FADH2 releases this amount of energy.

Coupling electron transport to ATP synthesis

Generates an electrochemical gradient across the inner mitochondrial membrane.

ATP Synthase

Enzyme that uses the proton gradient to synthesize ATP from ADP and Pi.

Porins

Channel forming proteins found in the outer mitochondrial membrane

Complex I

Also called NADH ubiquinone reductase or NADH- Q reductase, oxidizes NADH and transfers 2 electrons to ubiquinone.

Complex III

Called Q-cytochrome-c oxidoreductase and transfers two electron to cytochrome c

Complex IV

Also called cytochrome oxidase and transfers the two electrons from the two cytochrome-c proteins to the mitochondrial matrix to produce H2O

Complex II

Also known as succinate dehydrogenase or succinate-Q reductase, in the conversion of succinate to fumarate, FAD is reduced to FADH2