u3: electron transport chain

Question 1

before electron transport chain, where is most energy located?

Answer 1

in reduced electron carriers
- NADH
- FADH2

Question 2

where is cristae located?

Answer 2

outside of the inner membrane

Question 3

complexes in the electron transport chain

Answer 3

• complex I: NADH dehydrogenase
• complex II: succinate dehydrogenase
• complex III: cytochrome complex
• complex IV: cytochrome oxidase

Question 4

which complex is a single perpheral membrane protein?

Answer 4

complex II

Question 5

what mobile electron shuttles exist?

Answer 5

• UQ (ubiquinone): there are 2 of these, they move electrons from complexes I and II to complex III
• cyt-c (cytochrome-c): on intermembrane side, moves electrons from complex III to IV

Question 6

steps of electron transport chain

Answer 6

1. input NADH, donates two electrons and one H+, output NAD+
2. input FADH2, donates 2 electrons and 2 H+, output FAD
3. electrons from S1 and S2 are transported by electron acceptors, H+ stays in matrix
4. the movement of electrons in the inner mito membrane pumps H+ into the intermembrane space…=H+ gradient
5. electrons continue along ETC until they reach oxygen. 1 oxygen + 2 electrons + 2H+ becomes one H2O molecule

Question 7

proton-motive force

Answer 7

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

Question 8

define chemiosmosis

Answer 8

process in which ATP is synthesized using energy from electrochemical gradient in ATP synthase enzyme

Question 9

what is ATP synthase enzyme powered by?

Answer 9

• FADH2 and NADH has been used to create a H+ concentration gradient across inner mitochondrial membrane
• there is more H+ in intermembrane space than matrix
• the gradient powers ATP synthase enzyme

Question 10

steps of chemiosmotic synthesis of ATP

Answer 10

1. inner mito membrane stops passage of H+ ions = increase in H+ = increase in electrical potential
2. electrical potential passes through ATP synthase and converts into chemical energy
3. chemical energy is used to phosphorylate ADP + Pi into ATP

Question 11

what is ATP synthase

Answer 11

last enzyme in electron transport chain

Question 12

chemiosmosis formula

Answer 12

ADP + Pi 🡪 ATP

Question 13

what happens if u stop breathing?

Answer 13

• electron gets jammed in complex IV bc there’s no O2 to make H2O with
• no ATP is made