Question

Please explain why as well.

4. On average, how many ATP molecules are synthesized per NADH?

A. 0

B. 1

C. 2

D. 3

E. 4

5. The FADH2 that is produced donates its electrons directly to

A. Complex I

B. Complex III

C. Complex IV

D. Coenzyme Q

E. Cytochrome C

F. O2

6. In the Binding Change Mechanism the 3 conformational states that occur in the F1 subunit of ATP synthase depend on

A. interaction with b subunits

B. interaction with a subunits

C. interaction with g subunits

D. interaction with D subunits

7. Which of the following statement(s) about 2,4-dinitrophenol (DNP) is/are TRUE?

A. It is a hydrophobic compound

B. It uncouples electron transport from ATP synthesis

C. It diffuses through the inner mitochondrial membrane

D. It binds to protons

E. All of the above

8. Which of the following inhibitor(s), when used on isolated mitochondria, is/are likely to maintain/keep complex III in an oxidized state?

A. Rotenone

B. Cyanide

C. Azide

D. Carbon monoxide

E. A & B

F. A & C

G. B & D

H. C & D

9.A mutation in complex II would be expected to impair electron transport from which compound below?

A. Alpha-ketoglutarate

B. Succinate

C. Malate

D. Isocitrate

E. Acetyl-CoA

10. From the list below, choose the ONE site or step along the ETC that is not coupled to ATP synthesis.

A. Succinate to Coenzyme Q

B. NADH to Coenzyme Q

C. Coenzyme Q to Cytochrome C

D. Cytochrome C to O2

11. How does oligomycin work?

A. It is an uncoupler of oxidative phosphorylation

B. It inhibits NADH dehydrogenase

C. It blocks the flow of protons through F0

D. It is an inhibitor of cytochrome oxidase

Answer 1

4) electron transport chain(ETC) occurs in mitochondrion, it is the site of oxidative phosphorylation.

NADH,FADH2 generated in citric acid cycle are used in this produce to ATP by production of electrochemical gradient across membrane.

Electrons are transferred from higher potential to lower potential receiver like oxygen.

There are four complexes in ETC,which transport H+ ions across membrane.

For 1NADH molecule,

4 protons enter cell from complex-1

4protons enter cell from complex-3

2protons enter cell from complex-4

Total protons is 10.

For 1ATP to be synthesized 4protons should enter matrix from inner mitochondrial membrane.

So 4+4+2= 10 protons -2.5 ATP on average 3 ATP.

SO,answer is option D.

5)FADH2 is not a good electron donor as they are at low energy level so it can not directly give electrons to complex-1.

So it enters the ETC from complex -2 and donates electron to coenzyme-Q.and the chain continues it produces 2ATPmolecules.

So the answer is option D

6)answer is option A

IN ATP synthetase, there are two parts F0-F1.

F0 has many indentical c subunits,present in membrane.

F1 particle is attached to F0 in matrix facing direction.so it is literally in matrix of cell.

It's is kept hold in place by a and b subunits. b subunits is attached to F1 and a subunits is attached to F0 particle and put in place.

So b subunits attached to F1 is helpful in confirmational changes.basically, axle of F1 particle is used in confirmational changes that is gamma subunit.

9) answer is option B succinate

As complex 2 of ETC is succinate dehydrogenase.

10)answer is option D

Cytochrome C to O2