14C Assignment Flashcards
In a normal figure of mitochondrial ATP synthase, what side is the matrix side?
top of figure
bottom of figure
bottom of figure
The FO rotor in mitochondria has ~9 proton-binding hairpins (c subunits). In contrast, the FO rotor in chloroplasts has ~15 hairpins. Phosphorylation of each ADP to ATP by mitochondrial ATP synthase requires ( # ) protons to move from the crista space to the matrix. Reminder, the F1 lollipop has three active sites.
about three
about five
about nine
about fifteen
about one
about three
The FO rotor in mitochondria has ~9 proton-binding hairpins (c subunits). In contrast, the FO rotor in chloroplasts has ~15 hairpins. Phosphorylation of each ADP to ATP by chloroplast ATP synthase requires ( # ) protons to move from the thylakoid space to the stroma. Reminder, the F1 lollipop has three active sites.
about one
about three
about five
about nine
about fifteen
about five
In mitochondria, dimers of ATP synthase complexes:
pump protons in opposite directions
stabilize the extreme curvature of cristae membranes
produce two ATP for the price of one
create a localized proton sink/trap
two of the above
two of the above
Imagine a mitochondria ATP synthase mutant that is defective in the ability to dimerize. What would you predict regarding the topology of the mitochondrial inner membrane?
flattened, with indistinct cristae
more cristae packed into the same space
is unchanged
same number of cristae, but sharper than normal edges
flattened, with indistinct cristae
The “proton trap” that allows for efficient ATP synthase action in mitochondria is located:
in the cytosol
in the matrix
in the intermembrane space where the inner and outer membranes are close to each other
in the cristae spaces, near the rows of ATP synthase dimers
in the cristae spaces, near the rows of ATP synthase dimers
Movement of ADP and ATP across the inner mitochondrial membrane is:
active transport, because it requires ATP
simple diffusion
mediated by an antiport protein
mediated by an antiport protein
In which condition (below) is the proton gradient that drives nutrient uptake and Na+ export driven by an ATP synthase running in “reverse?”
anaerobic conditions
aerobic conditions
anaerobic conditions
In aerobic conditions, what produces the proton gradient?
ATP synthase
proton pumps of a respiratory chain
nutrient antiporters
proton pumps of a respiratory chain
In addition to favorable chemical gradients, what drives exchange of ATP and ADP across the inner mitochondrial membrane?
electrical gradient
ATP synthase
electrical gradient
Proton entry and exit from the F0 F1 ATP synthase complex occurs in channels between the:
stator and F0 rotor
F0 rotor and rotor stalk
rotor stalk and F1 ATPase head
rotor stalk and stator stalk
F0 rotor and F1 ATPase head
stator and F0 rotor
The ATPase rotor has a band of _____ charged amino acids right in the middle of the lipid bilayer in which it sits.
negatively charged
positively charged
uncharged
negatively charged
In a healthy cell, the mitochondrial ATPase rotor subunit spins at 8000 revolutions per minute. How much ATP is being synthesized per minute?
24,000 molecules
8000 molecules
2400 molecules
800 molecules
240 molecules
24,000 molecules
If a particular ATPase rotor has 12 alpha-helical hairpins, about how many protons must move through the complex before 1 ATP is produced?
12
8
4
2
1
4
Under so-called standard conditions where ATP, ADP, and Pi are equimolar, ATP hydrolysis yields about -30.5 kJ/mole. In fact, ATP is typically much _____ abundant than ADP in healthy cells, thus, the △G approaches -54 kJ/Mole.
more
less
similarly
more
