Unit 2 - ETC

Question 1

Summary of glycolysis, pyruvate oxidation and krebs products

Answer 1

1) - 2 ATP - 2 NADH
2) - 2NADH
3) - 2 ATP - 6NADH - 2FADH

we need to use our energy carriers to make 34 ATP using the ETC and oxidative phosphorylation

Question 2

ETC and Oxidative phosphorylation

Answer 2

• inner mitochondrial membrane
• 2 e- from NADH and FADH2 passed down a chain of oxidizing agents to O2 making water as its waste

Question 3

ETC

Answer 3

in the presence of O2, a series of mostly transport proteins built into the inner membrane is used to link electron transports to ATP synthesis

Question 4

ETC arranged how?

Answer 4

order of increasing electronegativity

Question 5

ETC carries NADH and FADH2

Answer 5

NADH is oxidized at NADH dehydrogenase releasing 2e-

FADH2 is oxidized at succinate dehydrogenase releasing 2e-

Question 6

Electrons flow downhill

Answer 6

electrons move in steps from carrier to carrier downhill to O2
- each carrier is more electronegative

Question 7

Reactions in ETC

Answer 7

a series of REDOX reactions occur between each protein complex to transfer the electrons
- two e- transferred each time
- as e- move down the ETC energy is released and the e- bc more stable

Question 8

at the end of ETC

Answer 8

the electrons have to reduce something! oxygen
Oxygen is reduced as it picks up 2e- and 2 protons

matrix is less acidic than the intermembrane space

Question 9

ETC 4 proteins complexes

Answer 9

• NADH dehydrogenase complex 1
• succinate dehydrogenase, complex 2
• cytochrome c reductase, complex 3
• cytochrome c oxidase, complex 4

Question 10

ETC 2 electron shuttles

Answer 10

• ubiquinone (Q or UQ)
• cytochrome c (cyt c)

Question 11

Oxidative Phosphorylation protein complex(two)

Answer 11

• ubiquinone
• cytochrome c

Question 12

1) path of electrons: NADH

Answer 12

2 electrons r dropped off by energy carriers: NADH drops e- off at complex 1, forms NAD+, complex 1 pumps protons (H+) across the inner membrane to the intermembrane space

Question 13

2) path of electrons: FADH2

Answer 13

FADH2 drops e- off at complex 2 forms FAD

Question 14

3. Ubiquinone

Answer 14

UB shuttles the e- from complex 1 and 2 to complex 3, which pumps protons (H+) across the inner membrane to the intermembrane space

Question 15

4. Cytochrome C

Answer 15

e- pass from complex 3 to cytochrome c, another electron shuttle

Question 16

5. Complex 4

Answer 16

cytochrome c shuttles the e- to complex 4. which pumps protons (H+) across the inner membrane to the intermembrane space

Question 17

6. complex 4

Answer 17

electrons from complex 4 combine w an oxygen atom in the matrix and 2 H+ ions to make water

Question 18

Pumping protons

Answer 18

• as electrons pass through the complexes they release some energy
• complex 1, 3, 4 use this energy to pump )H+) across the inner membrane to intermembrane space
• complex 2 and electron shuttles do NOT pump protons

Question 19

Oxidative Phosphorylation

Answer 19

as protons r pumped into the accumulate in the intermembrane space, a gradient forms:
- Chemical component
- Electrical Potential Component

Question 20

Chemical Component

Answer 20

higher concentration in intermembrane space

Question 21

electrical potential component

(PMF)

Answer 21

+ charges repel each other and r attracted to the - interior of matrix
form the Proton-Motive-Force (PMF)

Question 22

Proton Motive Force

Answer 22

a force that moves protons bc of a electrochemical gradient of protons across a membrane

Question 23

Intermembrane Space

Answer 23

is impermeable to protons which enables them to accumulate in the intermembrane space. To re-enter the matrix the protons must be pumped through the protein channel ATO synthase

Question 24

ATP synthase

Answer 24

has a channel that allows protons to move down their gradient and cross the inner membrane to the matrix = chemiosmosis

Question 25

Chemiosmosis

Answer 25

provides enough energy to make ATP from ADP + Pi

Question 26

Oxidative Phosphorylation

Answer 26

unlike substrate level phosphorylation, this involves a free Pi. a phosphate does not jump from another compound

Question 27

end of this

Answer 27

for every H+ proton through ATO synthase channel 1 ATP if formed

Question 28

DADH yields

Answer 28

3ATP so 10NADH x 3ATP = 30

Question 29

FADH2 yields

Answer 29

2ATP so 2FADH2 x 2ATP = 4

Question 30

Total ATP made via oxidative phosphorylation

Answer 30

34
(38 atp r made from the oxidation of 1 glucose)