FA/AMBOSS Electron transp and oxidation 12/27

Question 1

How is called Complex I?

Answer 1

NADH: ubiquinone oxidoreductase/NADH dehydrogenase

Question 2

How is called Complex II?

Answer 2

contains succinate dehydrogenase

Question 3

How is called Complex III?

Answer 3

Ubiquinone-cytochrome c oxidoreductase

Question 4

How is called Complex IV?

Answer 4

cytochrome c oxidase

Question 5

what transfers Complex I?

Answer 5

Transfers two protons (H+) and two electrons (e-) to coenzyme Q

Question 6

what transfers Complex II?

Answer 6

Transfers two protons (H+) and two electrons (e-) to coenzyme Q

Question 7

where an how many H pumps complex I?

Answer 7

Pumps four protons into the intermembrane space.

Question 8

equation of complex I?

Answer 8

NADH → NAD+ + H+ + 2 e-

Question 9

where an how many H pumps complex II?

Answer 9

Does not pump protons into the intermembrane space.

Question 10

equation of complex II?

Answer 10

FADH2 → FAD + 2 H+ + 2 e=

Question 11

what transfers Complex III?

Answer 11

Transfers two electrons (e-) from coenzyme Q to two molecules cytochrome c

Question 12

where and how many H pumps complex III?

Answer 12

Transfers 4 protons (H+) into the intermembrane space

Question 13

equation of complex III?

Answer 13

Reduced coenzyme Q (QH2) + 2 H+ + 2 oxidized cytochrome c → oxidized coenzyme Q + 4 H+ + 2 reduced cytochrome c

Question 14

main function of complex IV?

Answer 14

Reduces oxygen (O2) to water (H2O) via cytochrome a/a3 (Cu/heme protein)

Question 15

where and how many H pumps complex IV?

Answer 15

Pumps two protons (H+) into the intermembrane space

Question 16

the aim on transfer by complex IV (buvo prie IV, bet cia bendrai visu kompleksu I-IV)?

Answer 16

The transfer of electrons powers the transport of protons across the inner mitochondrial membrane into the intermembrane space → creates an electrochemical gradient across the inner mitochondrial membrane → powers the ATP synthase

Question 17

what tranfer complex IV?

Answer 17

Transfer of 4 H+ back into the mitochondrial matrix through ATP synthase (complex V) → phosphorylation of 1 adenosine diphosphate (ADP) → 1 adenosine triphosphate (ATP)

Question 18

equation for complex IV?

Answer 18

2 reduced cytochrome c + ½ O2 + 4 H+ → 2 oxidized cytochrome c + H2O + 2 H+

Question 19

how is called complex V?

Answer 19

ATP synthase

Question 20

how acts complex V?

Answer 20

Acts as proton channel, works like a turbine → flow of protons allows generation of ATP

Question 21

how mane H used and ATP generated via complex V?

Answer 21

For every 4 protons, one ATP is generated

Question 22

complex V. NADH equation?

Answer 22

1 NADH → transport of 10 H+→ 2.5 ATP

Question 23

complex V. FADH equation?

Answer 23

1 FADH2 → transport of 6 H+→ 1.5 ATP

Question 24

what are Respiratory chain inhibitors?

Answer 24

Rotenone: inhibits complex I
Antimycin: inhibits complex III
Cyanide, carbon monoxide, azides: inhibit complex IV

Question 25

what inhibits complex I?

Answer 25

Rotenone:

Question 26

what inhibits complex III?

Answer 26

Antimycin

Question 27

what inhibits complex IV?

Answer 27

Cyanide, carbon monoxide, azides

Question 28

what inhibits complex V?

Answer 28

block ATP synthesis by stopping the electron transfer via an increased proton gradient (e.g., oligomycin)

Question 29

prolonged tissue hypoxia on ATP production?

Answer 29

Prolonged tissue hypoxia (e.g., in myocardial infarction): lack of O2 molecules to accept the electrons NADH and FADH2 → disruption of the electron transport chain → decreased ATP production → cell injury or death

Question 30

what are 3 uncoupling agents?

Answer 30

Salicylic acid 2,4-Dinitrophenol Thermogenin

Question 31

mechanism of uncoupling agents?

Answer 31

Increased permeability of inner mitochondrial membrane → reduced proton gradient and increased oxygen consumption → electron transfer continues but ATP synthesis stops → production of heat

Question 32

what is thermogenin?

Answer 32

Thermogenin (in brown fat, which contains more mitochondria than white fat): a proton channel that physiologically uncouples electron transport and ATP synthesis to generate heat

Question 33

Salicylic acid (in high dosages; fever commonly develops after overdose)

Answer 33

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