Chapter 15

Question 1

Malate Asparatate system

Answer 1

NADH can’t cross, so malate does and enters cytosol

Can be dehydrogenated to oxaloacetate once across, which generates NADH

Oxaloacetate transanimated to aspartate which crosses back

Overall, 2 e- carried

Question 2

What can take 1 or 2 e-?
What has to take 1?
What has to take 2?

Answer 2

Ubiquinol: 1 or 2
FADH/NADH: 2
cyt. c: 1

Question 3

What can citrate transport be used for?

Answer 3

Getting Acetyl-CoA into cytosol for fatty acid synthesis

Question 4

What protein imports ADP into matrix and exports ADP to IMS?

Answer 4

Adenine nucleotide translocase

Question 5

How does mitochondria bring Pi into matrix?

Answer 5

Via H+ symporter

Question 6

What Ubiquinol Pool does

Answer 6

Shuttles e- from cytosolic NADH to Q, bypass complex 1

Question 7

Complex 1 path

Answer 7

NADH dehydrogenase (oxioreductase)

1) NADH –> NAD+, gives 2e-
2) FMN –> Fe-S center
3) –> Ubiquinone in C1 arm

Question 8

Complex 2 enzyme

Answer 8

Succinate dehydrogenase
(Acetyl-CoA dehydrogenase, mitochondria dehydrogenase)

Makes QH2

Question 9

Complex 3

Answer 9

Cytochrome b/C1 complex
Integral membrane protein 2e- –> Cyto C

ISP –> Cyto. C (functional core)
2nd e- on each round goes to cyt. b which regenerates QH2
Fe Heme group reduced

Question 10

Complex 4

Answer 10

Cyt. C oxidized (– >Fe 3+)

1) Cu redox center (CuA)
2) Fe-Cu center (Heme) where O2 reduced - binuclear center
3) 0.5 O2 + 2H+ –> H2O

Question 11

What makes up F0

Answer 11

alpha, 2x beta, c ring

Question 12

What makes up F1

Answer 12

3x alpha, 3x beta

Question 13

Rotation of c ring driven by

Answer 13

c ring

Question 14

Where is the proton binding site on c subunits

Answer 14

Carboxylate side chain of asparatate or glutamate

Question 15

alpha/beta bind to adenine, but only ___ has catalytic activity

Answer 15

beta

Question 16

ADP*Pi binds

Answer 16

Loose

Question 17

ATP in

Answer 17

Tight

Question 18

Release ATP in

Answer 18

Open

Question 19

Regulation of oxidative phosphorylation (ETC)

Answer 19

1) Availability of reduced cofactors drives oxidative phosphorylation (need NADH/QH2)
2) Needs ADP and Pi to make ATP
3) Mitochondria has regulatory protein that binds to ATP synthase and inhibits hydrolysis: pH sensitive. Binds if matrix PH drops due to momentary disruption of gradient. Prevents it from going in reverse.

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Question 20

Why does proton gradient not build up beyond typical 0.75 pH unit difference?

Answer 20

As soon as protons pumped into intermembrane spade, return to matrix via c ring of ATP synthase.