Electron Transport Chain

Question 1

key metabolic functions that occur in the mitochondria

Answer 1

oxidative phosphorylation
TCA cycle
beta-oxidation of fatty acids

Question 2

what is the function of the inner mitochondrial membrane

Answer 2

generates gradients of ions and compartmentalizes metabolites

Question 2

what is the electron transport chain

Answer 2

series of proteins and organic molecules that create a series of redox reactions that capture energy in a proton gradient

Question 3

what is the goal of the ETC

Answer 3

couple energy stored in electron acceptors to a protein gradient that drives ATP synthesis

Question 4

which complex oxidises NADH

Answer 4

complex I
NADH dehydrogenase

Question 5

which complex oxidises FADH2

Answer 5

complex II
succinate dehydrogenase

Question 6

which complexes pump protons

Answer 6

complex I, III, and IV

Question 7

what do complex I and II reduce

Answer 7

ubiquinone

Question 8

what reduces ubiquinone

Answer 8

complex III
cytochrome C reductase

Question 9

what does complex III reduce

Answer 9

cytochrome C

Question 10

what oxidises cytochrome C

Answer 10

complex IV
cytochrome C oxidase

Question 11

what does cytochrome C oxidase reduce
what does it produce

Answer 11

4 hydrogens and 2 oxygens
creates 2 H2O

Question 12

where is the ETC

Answer 12

inner mitochondrial membrane

Question 13

how does the NADH from glycolysis access the matrix to be used in the ETC

Answer 13

via malate:
the hydrogen is donated to form malate from oxaloacetate in the malate-aspartate shuttle
malate enters the mitochondria via transporter
malate oxidised back to oxaloacetate in the TCA cycle in the matrix producing NADH

Question 14

how does the NADH from the TCA cycle access the matrix to be used in the ETC

Answer 14

its produced there
TCA occurs in the matrix
;)

Question 15

what is the final acceptor of electrons in the ETC

Answer 15

water

Question 16

what are the overall functions of the ETC

Answer 16

regenerate electron acceptors for glycolysis and TCA cycle (NAD and FAD)
generate a proton gradient with a higher concentration of H+ in the IMS

Question 17

what is standard reduction potential

Answer 17

a measure of the ability to accept or donate electrons

Question 18

why is oxygen the found at the end of the ETC

Answer 18

it has the highest (most +ve) standard reduction potential
most likely to accept electrons

Question 19

why do we need to breath (in relation to ETC ofc not just “yOu’LL cHoKe”

Answer 19

to provide oxygen to act as the terminal electron acceptor allowing respiration

Question 20

what are prosthetic groups

Answer 20

cofactors that bind tightly to proteins or enzymes

Question 21

what prosthetic groups are involved in electron transport

Answer 21

1: flavin mononucleotides and ubiquinone
2: heme and ubiquinone
3: Fe-S clusters
4: Cu

[are the numbers the complexes or a list? research which complexes use which p groups]

Question 22

what does it mean that the Fe in heme is hexahedrally coordinated

Answer 22

it has 6 bonds

Question 23

what two things can happen to iron atoms when they enter the mitochondrial matrix

Answer 23

storage
used to make prosthetic groups

Question 24

what two pathways are used to make prosthetic groups from iron

Answer 24

heme pathway
iron-sulfur cluster pathway

Question 25

how do electrons flow through protein complexes

Answer 25

via a chain of redox reaction centres all very close in energy along a path through the complex

Question 26

what happens in cyanide poisoning

Answer 26

it inhibits complex IV
the ETC stops
the proton gradient decreases as diffuse back across the membrane

Question 27

what happens with the use of dinitrophenol (DNP)

Answer 27

acts as an uncoupling agent
IMM becomes leaky to protons
decreases ATP production
causes dangerously high body heat as a result of energy from ETC being released as heat not used to synthesise ATP

Question 28

how many ATP are generated in total from glycolysis, TCA cycle and ETC

Answer 28

38 xx