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WorksheetsThe Electron Transport Chain
Total questions: 53
Worksheet time: 1hrs 9mins
What is the usual AMP concentration within cells?
1.5nM
5nM
5mM
3nM
What does cytosolic AMP activate?
AMP-activated protein kinase (AMPK)
Glucose-6-phosphatase
Succinate Q oxidoreductase
Cytochrome c
Oxidative phosphorylation by the ETC consists of how many processes?
1
6
4
2
Which of these statements about the chemiosmotic theory is false?
There are two process involved in ATP synthesis that are indirectly linked
Movement of electron drives proton pumping
Protons are pumped from the intermembrane space into the matrix
The pumping of protons creates an electrical and pH gradient (proton motive force)
Protons move down their gradient through the phosphorylation apparatus to drive ATP synthesis
What is the other name for Complex I
NADH Q oxidoreductase
Q cytochrome c oxidoreductase
Succinate Q reductase
Cytochrone c oxidase
What is another name for Complex II
Q cytochrome c oxidoreductase
NADH Q oxidoreductase
Cytochrome c oxidase
Succinate Q reductase
What is another name for Complex III
Cytochrome c oxidase
Q cytochromc oxidoreductase
NADH Q oxidoreductase
Succinate Q reductase
What is another name for Complex IV
Succinate Q reductase
Q cytochrome c oxidoreductase
NADH Q oxidoreductase
Cytochrome c oxidase
Which complexes does Ubiquinone link to?
Complex III to Iv
Complex I to II
Complex I and II to III
Complex II and III to IV
Which small mobile electron carrier linked Complex III to IV
Cytochrome c
Ubiquinone
NADH
FAD2
The oxidation/ reduction reaction have decreasing redox potential
True
False
What is the approximate free energy of electron transport
-170 kJ/mol
-320 kJ/mol
-45 kJ/mol
-220 kJ/mol
The energy released from electron transport is used to pump protons
True
False
Iron-Sulphur clusters are found in which complexes?
I and II
I,II and III
II, III and IV
I, III and IV
Which option regarding Haem is incorrect?
a porphyrin ring structure with Fe chelated at the centre
found in complexes III and IV
Fe2+ <--> Fe3+ + e-
only found in cytochrome c
Where is copper found in the ETC?
Complex IV only
Complex III and IV
Complex II
Complex III
Which of the following is true regarding Complex I
It uses FADH2 and H+ as its substrate
4 electron pass from NADH through complex I
The process of electron transport is sufficient to power the pumping 2 H+ from the matrix into the IMS
NADH and H+ are freely diffusible in the matrix
The eletrons from complex I are passed onto:
Cytochrome c
Ubiquinone (Q)
Complex II directly
FAD
Complex II uses FADH2 as its substrate
True
False
Which of the following regarding complex II is false
FADH2 is not free as it is a prosthetic group of the enzyme
Succinate Dehydrogenase from the Krebs cycle is physically linked to substrate II
Electrons are passed onto Q, with 2 H+ ions from the matrix
4 electrons are passed from FADH2 to a series of FE-S clusters
Select all that are correct
Complex II doesn't fully span the membrane in the way Complex I does
No proton pumping occurs at Complex II
Complex I and II communicate
No proton pumping occurs at Complex II
FADH2 is free
Ubiquinone is also known as Co-Enzyme Q7
True
False
Select the option that is false regarding ubiquinone (Q)
Its long hydrocarbon tail makes it highly hydrophobic
Its hydrophobic nature means it is retained within the inner membrane
Uqiquinone can accepts 2 electron
Q can only accept electrons from Complex I
Complex III uses ubiquinol as its substrate
True
False
Select the true statement regarding complex III
It produces a cytochrome c as its product
It has to accept 2 e- but only release 1 e- at a time
It contains 2 cytochromes
It does not contain the Q cycle
2 H+ are moved into the intermembrane space by complex III
true
false
Select the false statement regarding cytochrome c
It transports 2 electrons from complex III to IV
It transports 1 electron from complex III to IV
It is water soluble
It contains a haem prosthetic group
Select all that are correct regarding Complex IV
It uses Cytochrome c and O2 as its substrates
O2 is the penultimate electron acceptor
Electrons flow through a haem/copper sandwhich
It only uses O2 as its substrate
O2 forms a peroxide bridge between terminal haem and copper
In Complex IV, what happens to the 2 cytochrome c?
It contains 4 electrons, 3 go along the chain to CuB and 1 goes along the chain to Haem a3
It contains 2 electrons which both go to CuB first, then Haem a3
It contains 4 electrons, 2 go along the chain to CuB and 2 go along the chain to Haem a3
It contain 2 electrons, 1 goes along the chain to CuB and 1 goes along the chain to Haem a3
O2 is taken up and forms a peroxide bridge between haem a3 and CuB
True
False
The addition of 2H+ ions turns the peroxide bring into H2O
True
False
2NADH or FADH2 are needed for Complex IV to reduce 1 O2
True
False
In Complex IV, how many protons are pumped into the IMS per O2?
2
4
8
Per NADH, how many H+ ions are pumped?
2
5
8
10
Per FADH2, how many H+ ions are pumped?
2
4
6
8
Select the true statement regarding phosphorylation
ATP synthase uses the H+ gradient to phosphorylate ADP to ATP
The proton gradient is used to power a "motor" that phosphorylates AMP to ATP
It is the electron gradient that powers ATP synthase
Select the correct order of events for ATP synthesis
1 this drives rotations of the gamma subunit
2 gamma subunit roations drives F1 subunit conformation changes
3 conformational changes of f1 drive phosphorylation of ADP
4 H+ flows through the F0 subunit
please answer in the form x,x,x,x (ie no space just a comma)
(a)
The F0 subunit catalyses ATP synthesis
true
false
Select the correct order for event in the F0 subunit
- 1 - Rotation of "c subunit" drives rotation of "gamma subunit"
- 2 - H+ enters through "a subunit"
- 3 - "gamma subunit" is linked to the F1 portion of ATP synthase
- 4 - H+ binds to asparatate residues in "c subunit", which neutralises the amino acids charge and this causes it to rotate in membrane
please answer in the form x,x,x,x (Ie no spaces, just commas)
(a)
To which amino acid residue does H+ bind in the F0 subunit?
alanine
aspartate
lysine
glutamic acid
How many beta subunits are there in the F1 subunit?
1
2
3
4
Each of the 3 beta subunits are conformationally the same
True
False
In the Open configuration:
ADP +Pi can enter and ATP leave
ADP + Pi are held in place
ATP is synthesised
In the loose configuration:
ATP is synthesised
ADP + Pi can enter, and ATP can leave
ADP + Pi are held in place
In the tight configuration:
ADP + Pi are held in place
ADP + Pi can enter and ATP can leave
ATP is synthesised
Each beta subunit must go through open, loose and tight how many times for 1 ATP to be synthesised?
twice
thrice
once
ATP synthesis can continue even if there is no H+ graident
true
false
In which year was the nobel prize in chemistry won for the elucidation of the enzymatic mechanism underlying the synthesis of ATP?
1988
1999
2001
1997
What is the purpose of the Adenine nucleotide translocase? Tick all that apply
Transports adenine
exchanges ATP and ADP from within the mitochondria to the cystol
discharges electrochemical gradient
makes the inside more positive (within the mitochondria)
The phosphate carrier takes a H+ away from ATP synthase to:
increase the electrochemical gradient
discharge the electrochemical gradient
increase the amount of phosphate outside the mitochondria
Put the experimental evidence into the correct order:
- 1 - Mitochondria only consume oxygen when stimulated by ADP.
- 2 - Increased ADP drives oxphos (not decreased ATP)
- 3 - Mitochondria stop consuming oxygen when all the ADP is phosphorylated to ATP
- 4 - Mitochondria with substrate consume minimal oxygen Mitochondria alone consume minimal oxygen
please answer in the form x,x,x,x (ie no spaces just commas)
(a)
Put the experimental evidence into the correct order
- 1 - ATP synthase uses the H+ gradient to phosphorylate ADP to ATP
- 2 - Oxygen is consumed as the terminal electron acceptor and water is made
- 3 - chemical inhibitors to any of the electron transport chain complexes with stop ATP synthesis
- 4 - H+ gradient is depleted
- 5 - Add in ADP to the isolated mitochondria- imported by ANT
- 6 - Electron transport is started; hydrogen carriers are oxidised, returning to the Krebs cycle
please answer in the form x,x,x,x,x,x (ie no spaces, just commas)
(a)
Select the incorrect answer regarding thermogenesis
It mainly occurs in white adipose tissue in newborns and hibernating animals
Uncoupling Protein 1 (thermogenin) is expressed in these tissues
Thermogenin dissipates the H+ gradient independently of ATP synthase, resulting in non-shivering heat generation
Uncouples oxidative phosphorylation so continue to oxidise fuel to generate proton gradient
