electron transport and oxidative phosphorylation Flashcards

1
Q

what does oxidative phosphorylation mean

A

the removal of electrons from metabolic intermediates and the synthesis of ATP from ADP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what processes can ATP help with

A

cofactor for signal transduction reaction using a variety of kinases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is the cellular ATP concentration usually

A

1-10mmol/L

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is the total quantify of ATP in an adult

A

0.1mol/L

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

how many mols/l of atp is required daily

A

100 to 150 mol/L

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

how many times is an ATP molecule recycled

A

1000-1500 times per day

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

how much percentage of atp does the mitochindria make

A

more than 95% of ATP to support aerobic respiration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what processes is the mitochondria also involved in

A

intracellular signalling
intracellular calcium regulation
cellular differentiation and growth and cellular death pathways

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is located in the mitochondrial matrix

A

an independent mitochondrial genome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

describe the mitochondria

A

the outer membrane- contains porins which allows for diffusion of ATP, ADP,CA,PHOSPHATE into the intermembrane space
the inner membrane- binds the matrix which is folded into cristae to increase the SA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

how does OP begin

A

by electrons entering the respiratory chain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

where do the electrons which are used in OP come from

A

the action of dehydrogenase from catabolic pathways- attached to NAD AND FAD

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is the equation for the breakdown of NADH

A

2NADH—> 2NAD+2H+ 4e-

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what happens to the electrons that are released from NAD

A

high energy electrons are passed from one complex to another down an electron chain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what are the complexes arranged in

A

increasing potential and increasing electron affinity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

how many complexes are there in the ETC

A

4

complex 1,2,3,4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what happens to the electrons when they reach complex 4

A

react with hydrogen and oxygen to form water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what happens as electrons move down the ETC

A

they release energy which allows hydrogen ions to be actively transported into the intermembrane space

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

how are the electron transporters arranged

A

organised into the membrane and embedded supramolecular complexes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

where does NADH drop electrons in the ETC

A

complex 1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

where does FADH drop electrons in the ETC

A

complex 2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what are the three electron carriers

A

ubiquinone
cytochrome c reductase
cytochrome c

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what is the first electron carrier

A

flavin mononucleotide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what does flavin mononucleotide do

A

it oxidises NADH to NAD and becomes reduced by accepting electrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
what is the name of complex 1
NADH-Q oxidoreductase
26
what is the pathway of FMN becoming reduced
``` flavin mononucleotide semiquinone intermediate flavin mononucleotide (reduced) ```
27
what needs to happen to the electrons for the energy to be released
passed down a number of iron sulphate complexes
28
how is iron bound to sulphur
a single iron atom is tetrahedrally coordinated with 4 SH--Cys groups
29
what happens to the iron molecules in this reaction
they can switch between fe2+ and fe3+
30
which amino acid is Sulphur found in
cysteine
31
how does the electron transfer oxidation and reduction occur
by direct transfer
32
what is the third electron carrier
co enzyme Q/ubiquinone
33
what happens to the electrons after they are carried by the FE-S complex
they are carried by ubiquinone which can diffuse rapidly within the inter mitochondria membrane
34
describe ubiquinone
it is a hydrophobic quinone which can diffuse across the membrane
35
what is the pathway of ubiquinone reduction
ubiquinone(full oxidised) semiquinone radical ubiquinol ( fully reduced)
36
what are the two functions in complex 1
1. the transfer to ubiquinone of a hydride ion from NADH and a proton from the matrix 2. pumps four protons into the IMS
37
what is complex two called
succinate dehydrogenase-
38
what is different about succinate dehydrogenase
the only membrane bound enzyme in the citric acid cycle
39
what is contained into complex 2
three 2[Fe-S] centres a bound FAD and a binding site for the substrate succinate
40
what is the electron pathway in complex 2
``` succinate binding site to FAD FE-S FE-S FE-S Q ```
41
what is the name of complex 3
cytochrome bc1
42
what occurs in cytochrome bc1
couples the transfer of electrons from ubiquinol to cytochrome c with the transport of H+ from the IMS
43
what is the coupling of the electron transfer from ubiquinol and the transport of H+ called
the Q cycle
44
what is complex 4 called
cytochrome c oxidase
45
what is contained in complex 4
2 heme groups and 2 copper centres
46
what does the copper centre do in complex 4
accepts electrons from reduced cytochrome c and reduces the second copper centre
47
what is the pathway of the electron in complex 4
1. first cooper centre accepts electrons from reduced cytochrome c and reduces the second copper centre 2. electron transfer to Fe in heme a2 3. both copper centre and iron in heme is in a reduced state 4. the iron centre binds with oxygen and the bound oxygen forms peroxide from the transfer of 2 electrons 5. the oxygen bridges the fe and cu- formation of the peroxide bridge 6. the third cytochrome c dumps electron and cleaves the O-O bond and takes a proton 7. the fourth cytochrome c dumps electrons and reduces the ferryl group 8. an uptake of 2 protons allows for the release of 2H20
48
how is ATP produced in ATP synthase
chemiosmotic hypotheses
49
what enzyme synthesises ATP
ATP synthase
50
how does the chemiosmotic hypothesis work
as protons are pumped into the membrane space it is now positively charged- results in an electric field with the mitochondrial matrix being negatively charged
51
how is the proton motive force calculated
chemical gradient + charge gradient
52
what is the symbol for proton motive force
delta p
53
what is the symbol for chemical gradient
delta pH
54
what is the symbol for charge gradient
delta psi
55
describe ATP synthase
two functional domains | f0 and f1
56
describe the f0 domain
is embedded into the inner mitochondrial membrane and has a proton pore through which protons leak a single unit binds to the outside
57
what are the subunits of ATP synthase
F1 F0 axle stator
58
describe the F1 matrix
it extends into the mitochondrial matrix and contains the catalytic activity of the synthase of ATP ADP+Pi---> ATP+H20
59
what is the free energy in the reaction of ATP synthase
free energy change close to zero | and is readily reversible
60
how many units does F1 contain
``` 5 units 3x alpha 3x beta delta epsilon and upsilon ```
61
what subunit connects the F1 unit to the F0 unit
epsilon and an external column called a stator
62
what does the F1 region do
binds the ADP +Pi catalyse the reaction of ATP release the ATP
63
what does the F1 region look like
3 alpha and 3 beta hexamer ring
64
which structure rotates in the F1
the gamma structure rotates only and not the alpha and beta
65
what is contained in the 3 alpha in the hexamer ring
contain bound ATP but does not participate in the reaction
66
what three states is beta found in the F1 structure
open loose tense
67
where is ATP released out of from the beta subunits of F1
only in the OPEN STATE
68
what happens in the tense state of the B subunit of F1
the ADP+Pi are close enough to produce ATP
69
what is the evidence of rotational catalysis
genetically engineered f1 allowed for the attachment of ATP synthase to a Ni complex biotin was covalently attached to C on F0 and the actin was labelled with a fluorescent probe and found to move when ATP was introduced as a substate
70
how are the electrons from NADH transported into the mitochondria
via the G3P shuttle
71
describe the G3P phosphate shuttle
1. a pair of electrons are transferred from NADH to dihydroxyacetone phosphate 2. forming glycerol 3 phosphate via the enzymatic catalysis using cytoplasmic G3P dehydrogenase 3. G3P is deoxidised to DHAP via G3P dehydrogenase 4. electron pair is transferred to FAD forming FADH2 5. the reduced flavin transfers the electrons onto Q cycle
72
what electron shuttle occurs in the liver and heart
the malate aspartate shuttle
73
describe the malate aspartate shuttle
1. electrons are transferred from NADH to oxaloacetate producing malate 2. malate then moves through the membrane and deoxidised by NAD+ via malate dehydrogenase 3. glutamine reacts with oxaloacetate forming aspartate 4. aspartate then moves out via the exit shuttle
74
how does ATP and ADP move into the inner mitochondrial membrane
ATP-ADP translocase
75
how many transporters are coded into the human genome
40
76
give some examples of the transporters coded by the human genome
``` ATP-ADP translocase dicarboxylate carrier tricarboxylate carrier pyruvate carrier phosphate carrier ```
77
what are other ways ATP can be produced
by uncoupled mitochondria- a type of brown fat adipose tissue generates heat contained in this is an unique uncoupling protein which bypasses the f0 and f1 complex so the energy of oxidation is dissipated as heat
78
what does 2,4 Dintrophenol do
it uncouples the electron transport by directly transporting proteins across the mitochondrial membrane- ATP not synthesised
79
what can 2,4 Dinitrophenol do
photographic chemical a fertiliser used in dyes and explosives was used for weight loss in 1933 but banned in 1938
80
what molecules inhibit the electron transport chain
rotenone antimycin A cyanide and carbon monoxide