The Electron Transport Chain, ATP Synthesis, and Mitochondrial Shuttles

Question 1

What 3 complexes pump electrons ?

Answer 1

complex 1: NADH Q oxidoreductase
complex3: cytochrome c oxidoreductase
complex 4: cytochrome c oxidase

Question 2

which complex does not pump any protons per eclectron?

Answer 2

complex 2 succinate Q reductase

Question 3

number of protons pumped per electron for complex 1-4

Answer 3

1. 4
2. 0
3. 4
4. 2

Question 4

the unlitmate electron acceptor in ETC ?

Answer 4

Oxygen

Question 5

the respirasome complex involves which complex

Answer 5

1,2,3

Question 6

hydrophobic molecule that diffuses rapidly in the membrane ?

Answer 6

ubinquinone

Question 7

in complex 1,where is the one hydride ion coming from?

Answer 7

NADH

Question 8

What is the one H+ used to form in complex 1 ?

Answer 8

QH2

Question 9

What is the source of NADH in complex 1 ?

Answer 9

TCA Cylcle, fatty acid B oxidation, a.a. catabolism

Question 10

iron cycles between +2(reduced) and +3(oxidized) in which complexes ?

Answer 10

complex 2 and 3

Question 11

heme b in complex 2 receives electrons and doesn’t protect against ROS T/F

Answer 11

F: heme b doesn’t receive electrons and DOES protect against ROS

Question 12

In complex 2 FADH2 forms __ ATP compared to __ ATP formed by NADH

Answer 12

1. 5

2. 5

Question 13

in complex 4 , __ protons are pumped per electron and _protons are pumped per catalytic cycle ?

Answer 13

2

4

Question 14

what are the heme and copper groups of complex 4

Answer 14

2 heme A groups (a and a3)

(Cu A/Cu A) and Cu B

Question 15

oxygen binding site in complex 4 of ETC species includes ?

Answer 15

Cu B and a3

Question 16

__ of ATP synthease protrudes into matrix while __ is in the membrane

Answer 16

F1

Fnot

Question 17

what powers the synthesis of ATP

Answer 17

Proton gradient b/w matrix and inner membrane space

Question 18

Peter Mitchell ?

Answer 18

ATP synthesis is coupled to e- transport via a proton gradient across the mitochondrial inner membrane

Question 19

Glycerol-3-phosphate shuttle ?

Answer 19

in muscle

mitochondrial glycerol-3-phosphate dehydrogenase (uses FADH2)

Question 20

Malate-aspartate shuttle

Answer 20

heart and liver)
Involves transport of malate/a-ketoglutarate and aspartate/glutamate across membrane
donates e-’s to complex I

Question 21

How does charged ATP4- exit, and how do ADP3- and phosphate ions enter, the matrix?

Answer 21

Via the ATP-ADP Translocase and the Phosphate Translocase

Question 22

Dicarboxylate shuttle ?

Answer 22

(phosphate/malate)

Question 23

Tricarboxylate shuttle ?

Answer 23

(malate/citrate

Question 24

pyruvate shuttle

Answer 24

pyruvate/OH-)

Question 25

phosphate shuttle

Answer 25

phosphate and OH

Question 26

Antimycin A: blocks flow through

Answer 26

COMPLEX 3

Question 27

CN-, N3- (azide), CO: inhibit

Answer 27

cytochrome oxidase

Question 28

Rotenone, amytal

Answer 28

block e- flow through complex I (but flow thru II possible)

Question 29

Inhibition of ATP synthase is by ?

Answer 29

Oligomycin, dicyclohexylcarbodiimide

Question 30

Chemical uncouplers, e.g., 2,4-dinitrophenol ?

Answer 30

e- transport can proceed, but ATP synthesis cannot

Question 31

Inhibition of ATP-ADP translocase

Answer 31

Atractyloside, bongkrekic acid

Question 32

in uncoupler UCP-1

Answer 32

oxygeen is consumed but ATP isn’t synthesized