8 Oxidative Phosphorylation Questions Flashcards
The P:O ratio refers to the amount of ATP synthesized per Oxygen converted to H2O. What effect will the presence of an uncoupling protein have on this ratio?
Introducing anything that creates a path for electrons to come back in without them going through the ATP synthase = the ratio will decrease (lowering efficiency of oxidative phosphorylation)
What is a potential consequence of uncoupling mitochondrial oxidative phosphorylation?
A.It allows continued mitochondrial ATP formation, but halts O2 consumption.
B.It halts all mitochondrial metabolism.
C.It slows mitochondrial ATP formation, but allows continued O2 consumption.
D.It will cause the pH of the intermembrane space to drop.
E.It reduces the rate at which NADH and FADH2 are re-oxidized.
What is a potential consequence of uncoupling mitochondrial oxidative phosphorylation?
A.It allows continued mitochondrial ATP formation, but halts O2 consumption.
B.It halts all mitochondrial metabolism.
C.It slows mitochondrial ATP formation, but allows continued O2 consumption.
D.It will cause the pH of the intermembrane space to drop.
E.It reduces the rate at which NADH and FADH2 are re-oxidized.
Isolated mitochondria are suspended in a medium containing succinate. The graph below shows O2 consumed and ATP synthesized over time in the mitochondria following the addition of various substances.
What is most likely added at time 1?
A.H2O
B.ADP + Pi
C.Glucose
D.ATP
A.H2O
B.ADP + Pi increase in O2 consumption and ATP synthesis - means we have provided the substrates for ATP synthesis (ADP and Pi). The system is coupled = increase ATP synthesis = Increase O2 consumption
C.Glucose
D.ATP
Isolated mitochondria are suspended in a medium containing succinate. The graph below shows O2 consumed and ATP synthesized over time in the mitochondria following the addition of various substances.
What is most likely added at time 2?
A.ADP + Pi
B.An uncoupler of oxidative phosphorylation
C.NADH
D.An inhibitor of ATP synthase
E.None of the above
A.ADP + Pi
B.An uncoupler of oxidative phosphorylation
C.NADH
D.An inhibitor of ATP synthase
E.None of the above
Isolated mitochondria are suspended in a medium containing succinate. The graph below shows O2 consumed and ATP synthesized over time in the mitochondria following the addition of various substances.
What is most likely added at time 3?
A.ADP + Pi
B.An uncoupler of oxidative phosphorylation
C.NADH
D.An inhibitor of ATP synthase
E.None of the above
A.ADP + Pi
B.An uncoupler of oxidative phosphorylation: electron transport is occurring (O2 consumed) but no ATP synthesis
C.NADH
D.An inhibitor of ATP synthase
E.None of the above
Which of the following statements is FALSE regarding oxidative phosphorylation?
A.Oxidation and phosphorylation are coupled via a proton gradient.
B.A positive difference in reduction potential is associated with a negative free energy change.
C.The pH is higher in the matrix relative to that in the inter-membrane space.
D.Electrons from FADH2 enter at complex II because the reduction potential of FADH2 is lower than that of redox centers in complex I.
A.Oxidation and phosphorylation are coupled via a proton gradient.
B.A positive difference in reduction potential is associated with a negative free energy change.
C.The pH is higher in the matrix relative to that in the inter-membrane space.
D.Electrons from FADH2 enter at complex II because the reduction potential of FADH2 is lower than that of redox centers in complex I. Lower in CII than in CI
