Cell Intgerity

Question 1

Site of oxidative phosphorylation

Answer 1

Inner membrane of mitochondria

Question 2

Reoxidation of NADH and FADH2

Answer 2

• NADH + H+ + ½ O2 → NAD+ + H20
• FADH2 + ½ O2 → FAD + H20

Question 3

Membrane proteins

Answer 3

• Complex I
  
  • NADH-Q oxidoreductase
• Complex II
  
  • Succinate-Q reductase
• Complex III
  
  • Q-cytochrome
• Complex IV
  
  • Cytochrome C oxidase

Question 4

Mobile electron carriers

Answer 4

Coenzyme Q ubiquinone
Cytochrome c

Question 5

Succinate dehydrogenase

Answer 5

Uses FAD as a cofactor
When electrons pass from FADH2 to coenzyme Q it picks up a pair of protons regenerating FAD and making QH2
Thus bypasses complex 1

Question 6

Why are less ATP molecules regenerated from reoxidation of FADH2

Answer 6

Less protons are lumped to the inter membrane space so protons flow back into matrix to make ATP

Question 7

Redox potential

Answer 7

The ability of a redox couple to accept or donate electrons
Positive means accepts electrons eg NAD+/NADH
Negativemeans donates electrons eg Fe3+/Fe2+

Question 8

ATP synthase

Answer 8

Contains F0 which is membrane bound
F1 projects into matrix space
If more protons are entering then atp synthesis

Question 9

Oxygen electrode

Answer 9

Measure’s concentration of oxygen
Oxygen diffuses through Teflon membrane and is reduced to water
Current is proportional to oxygen concentration in a chamber

Question 10

ATP consumption

Answer 10

Only 250g of ATO kept at any moment
OP failure due to hypoxia or anoxia

Question 11

Metabolic poisons

Answer 11

Molecules that interfere with flow of electrons along ETC or through ATP synthesis

Question 12

Rotenone

Answer 12

Inhibits transfer of electrons from complex I to ubiquinone

Question 13

Malonate

Answer 13

Has similar shape to succinate So acts as a competitive inhibitor
Slows down flow of electrons from succinate to ubiquinone by inhibiting oxidation of succinate to fumarate

Question 14

CN-/N3-

Answer 14

Bind to Fe3+ blocking final step of ETC complex IV and thus atp

Question 15

DNP

Answer 15

proton ionophore which can shuttle protons across inter mitochondrial matrix uncoupling OP from ATP production increasing metabolic rate and body temperature
Causes weight loss

Question 16

Oligomycin

Answer 16

Antibiotic that inhibits OP by binding to F0 of ATP synthase blocking flow of protons through enzyme

Question 17

Non shivering thermogenesis

Answer 17

Body detects drop in core body Temperature
Activates UCP1 so atp synthesis is bypassed and energy within H+ gradient generated as heat

Question 18

Order in which electrons flow from FADH2

Answer 18

Complex II coenzyme Q complex III cytochrome c and complexIV

Question 19

What does the F0 subunit of ATP synthase allow

Answer 19

Allows H+ flow between inter membrane space and matrix

Question 20

What do uncopulars do

Answer 20

Dissipate proton gradient