BCH 400 Oxidative Phosphorylation

Where does oxidative phosphorylation occur?

Inner mitochondrial membrane

What are the electron donors?

NADH and FADH2

What is the final electron acceptor?

Oxygen

What is the final product of oxygen reduction?

Water

What molecule is phosphorylated to form ATP?

ADP

What drives ATP synthesis?

Proton gradient

What is the chemiosmotic hypothesis?

Electrochemical gradient

In the electron transport chain, electrons move from ___ reduction potential to ___ reduction potential?

lower, higher

Is the flow of electrons in the electron transport chain endergonic or exergonic?

Exergonic

In the electron transport chain, where do NADH electrons enter?

Complex I

In the electron transport chain, where do FADH2 electrons enter?

Complex II

In the electron transport chain, what carries electrons from Complex I/II to III?

Coenzyme Q

In the electron transport chain, what carriers electrons from Complex III to IV?

Cytochrome c

In the electron transport chain, what complex transfers electrons to oxygen?

Complex IV

In the electron transport chain, what complex contains succinate dehydrogenase?

Complex II

In the electron transport chain, what complex(es) pumps protons?

Complexes I, III, IV

In the electron transport chain, which complex contains the Q cycle?

Complex III

In the electron transport chain, what follows Complex I?

Coenzyme Q

In the electron transport chain, what follows Complex II?

Coenzyme Q

In the electron transport chain, what follows Coenzyme Q?

Complex III

In the electron transport chain, what follows Complex III?

Cytochrome c

In the electron transport chain, what follows cytochrome c?

Complex IV

In the proton gradient, where are protons pumped?

Intermembrane space

In the proton gradient, where do protons originate?

Mitochondrial matrix

In the proton gradient, where do protons return?

Mitochondrial matrix

In the proton gradient, what membrane separates these compartments?

Inner mitochondrial membrane

What does the proton gradient store?

Potential energy

What happens when the proton gradient dissipates?

ATP production decreases

What is Complex V?

ATP synthase

What is the membrane portion of ATP synthase?

Fo

What is the catalytic portion of ATP synthase?

F1

What causes ATP synthase to rotate?

Proton flow

What are the three beta-subunit conformations?

Loose, Tight, Open

Which conformation binds ADP and Pi?

Loose

Which conformation forms ATP?

Tight

Which conformation releases ATP?

Open

What inhibits Complex I?

Rotenone

What inhibits Complex III?

Antimycin A

What inhibits ATP synthase?

Oligomycin A

What inhibits Complex IV?

Cyanide

What is an example of an uncoupler?

2,4-DNP

What does an uncoupler destroy?

Proton gradient