ETC Flashcards
where are the FADH2 and NADH generated from TCA, beta oxidation, etc located
mitochondrial matrix
order of e- carriers
- NAD
- FAD/FMN
- CoQ
- Hemes
- Fe-S clusters
- Cu clusters
where does NADH come from
malate aspartate shuttle
lactate shuttle
TCA cycle
where does FADH2 come from
TCA cycle
glycerol phosphate shuttle
if a poison blocks a step in the ETC, all the carrier downstream will be ____ and all thec arrier upstream will be ____
oxidized, reduced
NADH carries
2 e- and 1 H+
NADH assocation
reversible association with proteins -> soluble
FAD/FMN can carry
FADH (FAMN) can carry 1 e- and 1 H+
FADH2(FAMN2) can carry 2 e- and 2 H+
FAD/FMN associatoin
tightly bound to proteins
FAD/FMN reduction potential
vary significant;y with protein microenvironemtn
most oxidized form of coq
ubioquinone
unioquinone’s long chain HC allows what
be inside the inner mitochondrial membrane, membrane soluble
most reduced form of coq
ubiquinol
radical form of coq
semiquinone radical
*QH carries
1 e- and 1 H+
QH2 carries
2 e- and 2 H+
coq association
reversible association with proteins
heme carries
1 e-
heme association
tightly bound or covalently bonded to proteins
how does heme form
reduction of Fe3+ to Fe2+
cytochrome
protein with bound heme
Fe-S clusters carry
each Fe in an Fe-S cluster can carry 1 e-
Fe-S association
covalently bonded to proteins by cysteine side chain sulfur ligands
Cu centers carry
1 e-
copper center reduction equation
2Cu1.5+ plus e- yields 2Cu 1+
Cu centers assocation
covalently bonded to proteins by cysteine side chian sulfur ligands
P/O ratio
ATP produced per O2 reduced
are complex 1, 3, and 4 coupled firectly to ATP production
no
intermembrane space charge
positive
matrix charge
negative
p side
intermembrane
n side
matrix
delta g for pumping proton across membrane (from n side to p side)
18.9 kj/mol
since the pathway of reduction from NADH to H2o can produce 200 kj of energy, how many H+ can be pumped to the p side using this energy
10 H+
how H+ does complx 1 pump to the P side
4 H+
how H+ does complx 3 pump to the P side
4 H+
how H+ does complx 4 pump to the P side
2 H+
input for complex 1
NADH
where do electrons go in complex 1
coenzyme q
complex 1: where do the electrons to make qh2 come from
matrix
how is e- transfer able to move H+ across membrane in complex 1
each e- transfer changes the conformation of a protein which produced mechanical energy that can be used to pump protons; each conformational change grabs proton from membrane side and pushes it across
input in complex 2
succinate (from TCA cycle)
where do electrons end up complex 2
ubiquinone
purpose of complex 2
oxidize FADH2 and move those electrons into ubiquinone, no protons pumped
what TCA enzyme is complex 2
succinate dehydrogenase
complex 3 where do e- come from
ubiquinone
complex 3 where do e- go
cytochrome c
how many protons pumped directly from QH2 in the q cycle
4 H+
net equation for the Q cylce
QH2 + 2 cyt c (oxidized) 2H+n -> Q + 2 cyt c (reduced) + 4H+p
input substrate for complex 4
cyt c
why does there need to be 2 cycles of complex 4
there are 2 cyt c coming from 1 cycle of complex 3
- need 4 cyt c to fully reduce O2 2- ( 2 e- for reducing o2 and 2e- to make h2o)
site of o2 reduction is the
Cub-Fe heme center
net reaction for complex 4
4 cyt cred + 8H+ N + O2 -> 4 cyt c ox + 4 H+ p + 2 H2O
why are there 8 matrix electrons in complex 4
4 for substrate (making H2O), 4 are pumped
why does O2 have to be o22-
make it bind covalently to copper
how are protons pumped in complex 4
protons hop between acidic side chains (D and K)
how many H+ pumped per FAD
6
respiratory supercomplex
tightly associating complex can make reactions faster and more efficient
where did the NADH protons come from
food
where did the FADH2 protons come from
food
where did the Q protons come from
matrix
how many protons will be used in generating one ATP on complex 5
one nadh pumps 10 protons, one nadh worth 2.5 atp, so 4 protons used per atp
