metabolic pathways and ATP production

Question 1

structure of mitochondria

Answer 1

diagram from metabolism 5

Question 2

what does cristae do

Answer 2

increases SA so increases ATP production

Question 3

describe the endosymbiotic theory

Answer 3

originially prokaryote; endosymbiosis with ancestory eukaryotic cell and genes incorporated into nucleus

Question 4

5 items of evidence to support endosymbiotic theory

Answer 4

mt only arise from existing mt, possess own genome as circular DNA, prokaryotic protein synthesis machinery, 1st amino acid (fMet) same as prokaryotes, antibiotics vs bacteria work on mt also

Question 5

describe the electron transport chain

Answer 5

NADH is oxidised to NAD+ and H+ → 2e- reduce NADH dehydrogenase complex and passed to CoQ (ubiquinone) → reduce cytochrome b-c1 complex then bind to cytochrome C → reduce cytochrome oxidase complex and bind to final e- acceptor oxygen along with 2H+; every reduction is associated with H+ being pumped from matrix into intermembrane space across inner mitochondrial membrane

Question 6

explain chemiosmotic theory

Answer 6

mechanism using energy stored in transmembrane H+ gradient to drive active process (ATP, transport)

Question 7

diagram of electron transport chain

Answer 7

diagram

Question 8

what bind to Fe3+ in cytochrome oxidase complex and block e- flow

Answer 8

CN-, N3-

Question 9

what inhibits e- transer in NADH dehydrogenase complex

Answer 9

rotenone

Question 10

what does DNP do in the electron transport chain

Answer 10

shuttles H+ back across into matrix but is not associated with ATP synthase (acts as an uncoupler)

Question 11

what must successive redox potential be in order for the e- to continue along the electron transport chain

Answer 11

higher; e- transfer is energetically favourable, so e- lose energy

Question 12

diagram of redox potentials across electron transport chain

Answer 12

diagram

Question 13

give the equation concerning NADH for oxidative phosphorylation

Answer 13

NADH + H+ + 1/2O2 → NAD+ + H2O

Question 14

give the equation concerning FADH2 for oxidative phosphorylation

Answer 14

FADH2 + 1/2O2 → FAD + H2O

Question 15

ATP synthase: what drives transition states and what is the outcome

Answer 15

rotation of rotor; alter affinities for ATP and ADP

Question 16

ATP synthase: what are F0 and F1

Answer 16

F0: membrane bound section; F1: section projecting into matrix (rotor and stator)

Question 17

ATP synthase: when is hydrolysis favoured

Answer 17

when higher [H+] and [ATP] in matrix

Question 18

ATP synthase: when is synthesis favoured

Answer 18

when lower [H+] and [ATP] in matrix

Question 19

ATP synthase: what does membrane-bound succinate dehydrogenase do

Answer 19

communicates with CoQ (ubiquinone) which passes the e- to NAD+

Question 20

ATP synthase: consequence of succinate dehydrogenase

Answer 20

1 less H+ pumped through

Question 21

ATP synthase: what inhibits succinate dehydrogenase

Answer 21

malonate

Question 22

what does the oxygen electrode do

Answer 22

measures [oxygen] in solution housed in small chamber (experiment for respiration)

Question 23

what is the base of the oxygen electrode formed from

Answer 23

oxygen-permeable teflon membrane

Question 24

diagram of oxygen electrode

Answer 24

diagram