BIOL 3200 Electron Transport Systems

Electron Transport Systems (ETS)

Electrons will flow from carriers with more negative reduction potentials

Where does NADH and FAD2H go in the ETS?

Electrons are donated to bacterial ETS to generate ATP by oxidative phosphorylation

Where are Gram-positive ETS?

In the cell membrane

Where are Gram-negative ETS?

In the inner membrane

What happens as electrons move from protein to protein?

Protons are pumped out of the cell

What does aerobic respiration use as its terminal electron acceptor?

Oxygen

What does anaerobic respiration use as its terminal electron acceptor?

Any other electron acceptor, NOT oxygen

What is the proton motive force?

The ETS generates an electrochemical gradient of protons

Electron Transport System of E. Coli

How does mitochondrial ETS differ from E. Coli ETS?

1) Possesses intermediate ubiquinol: cytochrome C oxidoreductase complex
2) Mitochondrial ETS pumps 12 H+ per NADH, 2 more than E. Coli

What does extra oxidoreductase mean?

More proton force which means more ATP

What does ATP synthase do?

Converts ADP to ATP

What is the chemiosmotic theory?

The presence of a proton motive force driving the conversion of ADP to ATP

ATP synthesis by chemiosmosis is similar in what?

Bacteria, mitochondria, and chloroplasts

What is the process of ATP synthesis by chemiosmosis in bacteria?

Protons are pumped from the cytosolic face to the exoplasmic face

What is the process of ATP synthesis by chemiosmosis in mitochondria?

Protons are pumped from the matrix to the intermembrane space

What is the process of ATP synthesis by chemiosmosis in chloroplasts?

Protons are pumped from the stoma to the thylakoid lumen

What is the synthesis of ATP?

Protons flow down electrochemical gradient through ATP synthase

What happens to nitrate when some bacteria use it as their terminal electron acceptors?

Nitrate is reduced to nitrite

What happens to sulfur when some bacteria use it as their terminal electron acceptors?

Sulfate is reduced to sulfite