Cell Metabolism ETC

Question 1

describe the structure of a mito

Answer 1

outer CM
inner CM
IMS
matrix

Question 2

what type of phosphorylation occurs in mito

Answer 2

OP ( not SLP)

Question 3

what membrane proteins are involved in the ETC

Answer 3

complex I ( NADH dehydrogenase) 
Complex II ( succinate dehydrogenase) 
complex III ( Q-cytochrrome C oxidoreductase) 
complex IV ( cytochrome C oxidase)

Question 4

what mobile carriers are involved in the ETC?

Answer 4

coQ

cytochrome C

Question 5

what is the function of cytochrome II

Answer 5

succinate dehydrogenase
enzyme in the TCA cycle that turns succinate coA
FADH2 –> FAD+ e- given to CoQ ( + 2H+)–> QH2

Question 6

what cofactors are involved in ETC

Answer 6

NAD

FAD

Question 7

where else is complex II found

Answer 7

TCA –> succinate dehydrogenase converts succinate –> fumerate

Question 8

why does FADH2 produce less E than NADH

Answer 8

FADH bypasses CI –> less H+ in IMS

less H+ goes through ATP synthase

Question 9

What are the functions of ATP synthase

Answer 9

ATp synthesis , ATP hydrolysis

Question 10

what controls the function of ATP synthase

Answer 10

H+ flow
H+ from IMS –> matrix ( synthase )
H+ form matrix –> IMS (hydrolysis)

Question 11

how does ATP synthase make ATP

Answer 11

consists of 2 subunits F0 F1,

rotation of enzyme –> different transition state –> diff affinity for ATP / ADP

Question 12

what is hypoxia

Answer 12

diminished O2

Question 13

what is anoxia

Answer 13

total O2 loss

Question 14

name 5 metabolic poisons

Answer 14

Cn- ( cyaninde) 
azide ( N3-) 
rotenone 
oligomycin 
malonate 
DNP

Question 15

How does CN-/N3- stop the ETC

Answer 15

inhibits CIV ( high affinity to Fe 3+ in CIV) –> backs up ETC

Question 16

How does malonate stop the ETC

Answer 16

competitively binds to CII –> slows down e- transmission to ubiquinone
inhibits oxidation of succinate –> fumerate

Question 17

how does rotenone stop the ETC

Answer 17

inhibits CI –> less H+ to IMS

Question 18

How does oligomycin stop the ETC

Answer 18

binds to stalk of ATP synthase

prevent H+ flowing through ATP synthase to matrix

Question 19

How does DNP stop the ETC

Answer 19

uncouples H+ from ATP synthesis

H+ can cross membrane w/o going through ATP synthase

Question 20

what is a redox couple

Answer 20

substance that can be reduced and oxidised

Question 21

name an example of a redox couple

Answer 21

NADH/NAD+
FAD/FADH2
Fe2+/Fe3+
1/2O2/H2O

Question 22

what is a redox potential

Answer 22

ability to donate / accept e-

Question 23

what does a -ve E0 mean

Answer 23

higher reducing power than H tend to donate e-

Question 24

what does a +Eo mean

Answer 24

less reducing power to H tend to accept e-

Question 25

what is an O2 electrode used for

Answer 25

current proportional to o2 conc

use to monitor effect of metabolic poisions

Question 26

if in a test tube with mito I add glucose rotenone citrate then oligiomycin what would happen to o2 consumption

Answer 26

stationary ( glucose can’t diffuse across)
stationary ( rotenone has no effect since no carbs can be used as feul)
increase ( citrate acts as fuel for TCA cycle as can make succinate )
decreases as ATP synthesis blocked

Question 27

what would happen to O2 conc if succinate added then DNP added then malonate

Answer 27

increase succinate –> e- for CII
decrease as DNP uncouples ATP synthesis
slows drastically as CI not used

Question 28

what happens to O2 levels if if citrate then CN- then DNP added to mito

Answer 28

increase
then decrease ( terminal e- acceptor blocked)
stays same as no terminal e- to accept e- –> backlog of ETC