What is the main role of cytochrome aa3?
Takes e- from ubiquinol and reduces oxygen to water
Takes e- from ubiquinol and reduces oxygen to peroxide
Takes e- from cytochrome c and reduces oxygen to peroxide
Takes e- from cytochrome c and reduces oxygen to water
Complex IV contains how many subunits?
Complex IV doesn't transfer protons across the inner mitochondrial membrane
Which ions does it contain, and how many of each?
2 Fe (in haeme groups) and 3 Cu (2 as a Cu-Cu binuclear centre, 1 as a binuclear Fe-Cu centre)
2 Cu (in haeme groups) and 3 Fe (2 as a Fe-Fe binuclear centre, 1 as a binuclear Fe-Cu centre)
2 Mg (in haeme groups) and 3 Cu (2 as a Cu-Cu binuclear centre, 1 as a binuclear Fe-Mg centre)
Cytochrome aa3 complex consists almost entirely of alpha helices
Put the following in order
A- Cyt c
B- CuA centre
C- Cyt a
D- Cyt a3-CuB centre
E - Water
•Transfer from cyt a3-CuB centre to oxygen
How many protons are pumped by complex 4, and how many are used to make water (per Oxygen molecule)?
4 & 4
4 & 2
2 & 4
Which conformation of Complex IV has the low affinity for protons?
Protons bind to Complex IV during Conformation B
What happens during conformation B that lowers the Complex IV's affinity for protons?
Energy is put in
Energy is lost
The protein has an Fe group added
No question, just look at it and learn it
ATP synthase is found on the inner mitochondrial membrane
ATP synthase is divided into two sections, F1 & F0
Which is peripheral and which is integral?
F1 is peripheral
F0 is integral
F0 is peripheral
F1 is integral
Name the function of ATP synthase
If ATP is high, and the proton gradient is low, what will Complex V do instead?
Break itself down
Protons flow through F1 to power the ATP synthesis in F0
Name the subunits of F1
Which of the following subunit(s) are the largest in F1?
Alpha & Beta
Gamma & Delta
Beta and Gamma
Alpha and Epsilon
What is the role of the delta subunit in F1?
Stabiliser for the F1 head
Connets F1 too F0
The epsilon subunit of F0 connects the gamma to the C subunit
F0 contains how many subunits?
2- A & B
3- A, B & C
2- Alpha & Beta
The F1 subunit is...
The Y subunit of F1 is made of 2 beta sheets that have been bent, but are bound at the base
When the gamma subunit is in contact with a beta subunit, the ATP catalysis site is in it's _ formation
A subunit contains ADP + Pi- what conformation is it in?
Whilst the subunit is replacing ATP with ADP + Pi, the gamma subunit remains in plance
What order do the three conformations work in?
Assume you start with the Loose formation
State the characteristics of the C subunit of F0
How many monomers make up the C subunit?
The C subunit contains 3 rings of monomer
Why is there a variance across species of the number of monomers in the C subunit?
The more complex an organism, the more efficient the subunit
The more complex an organism, the less efficient the subunit
The larger the organism, the more subunits are required
Mammals have 8, birds have 12, all lesser animals and prokaryotes have 14 or more
More subunits require more protons to move them, so more subunits is less efficient
How is the A subunit described?
A proton half channel
A proton channel
A proton quarter channel
Protons passing through the A subunit...
Use it to enter the C subunit and exit to the cytoplasm
Use it to exit into C subunit and enter from the cytoplasm
Each subunit can hold 2 protons
The momevent of the protons around the C subunit powers what?
The movement of the gamma subunit
The conformational changes of the beta subunits
The attachment of the alpha subunits
The rotation of the delta subunit
The rotation of the F1 has been proved by attaching a microtubule filament to the F1 head and examining it under the microscope
Only the gamma subunit of the F1 complex rotates
How is the Alpha/Beta spheroid of F1 held in place?
For every _degree rotation, 1 molecule of ATP is produced
The mechanism of the gamma subunit causes an affinity change for ATP/ADP + Pi, driving the cycle