[Biochem Lec] The Electron Transport Chain

Electron Transport Chain

Is a multistep process using 4 enzyme complexes (I, II, III, IV) located along the mitochondrial inner membrane.

• NADH-Q-oxidoreductase

• Succinate-Q-reductase

• Cytochrome reductase

• Cytochrome oxidase

What are the complexes used in electron chain transport

Redox reaction

Electron transport chain is a series of?

Fixed/Stationary

the 4 complexes are mobile or fixed in the inner mitochondrial membrane?

II - Succinate-Q-reductase

All complexes are proton pumps except?

• Ubiquinone/Co-enzyme Q10

• Cytochrome C (Cyt C)

Other substances that facilitate ETC and are also mobile or they have the ability to “Shuttle”

• Ubiquinone (Co-Enzyme Q10)

• Cytochrome C (Cyt C)

What are the electron carrier enzyme in the ETC

Ubiquinone (Co-enzyme Q10)

The only non-protein component/enzyme/complexes in ETC

Ubiquinone (Co-Enzyme 10)

What complexes is/are hydrophobic in nature?

Ubiquinone (Coenzyme Q10)

I and II electron carriers

Cytochrome C (Cyt C)

III and IV electron carriers

Intermembranous Space

If 3 proton pumps are activated, it will saturate the _________ with protons

Oxygen

Final electron acceptor?

Electrons

Serves as energy form for the movement of proton across complexes?

Reducing equivalents from Kreb’s cycle

Source of energy (electrons) for the movement of protons across complexes

Oxidation

What reaction occurs when NADH loses an electron as an energy source for complexes

FADH2

Electron source of complex II

NADH

Electron source of complex I

Electron from complex i and II through ubiquinone

Electron source of complex III

Electron from complex III through cytochrome C

Electron source of complex IV

Complex IV (Cytochrome oxidase)

Where is oxygen located in ETC to fulfill its duty as a final electron acceptor?

Water

Reduced form of oxygen?