Matching Questions
Use the following to answer questions 1-10:
Choose the correct answer from the list below. Not all of the answers will be used. a) Peter Mitchell b) chemiosmotic theory c) binding-change d) loose e) ATP f) entropy g) α subunit h) tight
i) glycerol 3-phosphate shuttle j) c ring
k) ATP-ADP translocase l) malate-aspartate shuttle m) Sir Hans Krebs
418
____________ The thermodynamic driving force of ATP synthesis due to pumping of protons.419
____________ first described the chemiosmotic hypothesis.420
____________ is the mechanism for the proton-driven ATP synthesis.421
____________ Which form of the ATPase subunits is responsible for phosphorylation of ADP?422
____________ Rotation of this, driven by proton gradient, powers ATP synthesis.424
____________ Dihydroxyacetone phosphate is part of the ______________ shuttle.425
____________ This is the name given to the hypothesis proposed by Peter Mitchell to explain how ATP synthesis is coupled to electron transport.426
____________ Atractyloside inhibits this mitochondrial protein.427
____________ This is a process by which cytoplasmic NADH can be reoxidized by O2 usingthe electron-transport system.
Fill-in-the-Blank Questions
428
Transfer of electrons from NADH leads to how many ATP? .429
membrane protein couples the entry of ADP into the mitochondrial matrix with the exit of ATP.430
The protein involved with thermogenesis by uncoupling electron transport from oxidative phosphorylation is .431
is a molecular assembly in the inner mitochondrial membrane that carries out the synthesis of ATP.432
In the glycerol phosphate shuttle, cytoplasmic glycerol phosphate dehydrogenase uses cytoplasmic NADH to reduce to glycerol-3-phosphate.433
Acceptor control of oxidative phosphorylation means that the rate of respiration depends on the level of .435
In the presence of respiration continues but no ATP is formed.436
The antibiotic inhibits the flow of protons through ATP synthase.437
ATP is transported out of the mitochondria by the antiporter .Multiple-Choice Questions
438
What type of gradient is critical to ATP formation by oxidative phosphorylation?A) sodium ion D) potassium ion
B) chloride ion E) None of the above.
C) proton
439
When glucose is totally oxidized to CO2 and H2O, how many ATP molecules are made byoxidative phosphorylation relative to the maximum yield? A) 12 out of 30
B) 26 out of 30 C) 26 out of 32 D) 12 out of 38 E) None of the above.
440
What is the chemical effect of rotenone on aerobic metabolism? A) The flow of electrons from NADH to CoQ is blocked.B) The flow of electrons from Cyt a-a3 to oxygen is blocked.
C) Oligomycin blocks the proton transfer through F0 of ATP synthase and therefore blocks the
phosphorylation of ADP to form ATP.
D) The transport of ATP out of and ADP into the mitochondria are blocked.
E) Oxidative phosphorylation is uncoupled from electron transport and all the energy is lost as heat.
441
The subunit of the ATPase embedded in the inner mitochondrial membrane is the __________. A) anchor subunitB) membrane-c ring subunit C) F0 subunit
D) F1 subunit
442
The F1 component of ATP synthase is composed of _________.A) three α subunits B) three β subunits C) a Δ subunit D) All of the above. E) None of the above.
443
The proton motive force consists of _____________.A) a chemical gradient D) A and B.
B) a proton gradient. E) A, B, and C.
C) an electron gradient
444
Electron flow down the electron-transport chain leads to theA) transport of protons across the inner mitochondrial membrane from inside the matrix to the intermembrane space.
B) transport of protons across the inner mitochondrial membrane from the intermembrane space into the matrix.
C) coupled synthesis of GTP.
D) a dangerous imbalance of K+ ions across the mitochondiral membrane.
E) None of the above.
445
How does the rotation of the c ring lead to ATP synthesis?A) The c ring is linked tightly to the gamma and epsilon subunits in the stalk of F1.
B) The c ring interacts with the beta subunit.
C) The gamma subunit rotates with proton gradient formation inducing the binding-change mechanism.
D) All of the above. E) None of the above.
446
What are the driving force (energetic) costs for the ATP-ADP translocase? A) entropy – concentration gradient of ATPB) membrane potential from electron transport C) active transport by Na-K ATPase
D) All of the above. E) None of the above.
447
A diet pill that acts to increase oxygen consumption and a high amount of electron transport without ATP production is likely what kind of compound?A) uncoupler
B) ATP synthase activator C) site I inhibitor
D) site II activator E) cyanide
448
What is the reaction of ATP synthase? A) AMP3 + 2 HPO 42 + H+ ATP4 + H2O B) ADP3 + HPO 42 + H+ ATP4 + H2O C) ADP3 + HPO 42 + 2H+ ATP4 + H2O D) AMP3 + 2 HPO 42 + 2H+ ATP4 + H2OE) None of the above.
449
What is the net ATP obtained from one cytoplasmic NADH when it is oxidized by the electron- transport chain using the glycerol 3-phosphate shuttle?A) 2.5. B) 1.5. C) 2.0. D) 1.0. E) None of the above.
450
In the malate-aspartate shuttle, electrons from NADH are transferred to ________, forming malate.A) oxaloacetate D) glutamate
B) aspartate E) None of the above.
C) acetate
451
Suppose there is a mutation in the c subunit of ATP synthase, such that the glutamate found in the middle of one of the membrane spanning helices is converted to a valine. What is likely to be the effect on ATP synthesis and why?A) No effect. The middle of the helix is in contact with the hydrophobic center of the lipid bilayer and the valine is readily soluble in lipid.
B) No effect. The valine side chain is shorter than the glutamate side chain, so it causes no change in the secondary structure of the helix.
C) Inhibit ATP synthesis. Valine cannot bind a proton, so there will be no proton flow through the inner membrane.
D) Inhibit ATP synthesis. Because valine is hydrophobic, the α subunit will move in the reverse direction, causing the hydrolysis of ATP, not synthesis.
E) Increase ATP synthesis. Because the valine side chain is hydrophobic, the α subunit can move easily without regard to oxidative processes.
452
Why is it not surprising that substances such as intermediates for the citric acid cycle, protons, inorganic phosphate, nucleotide phosphates, and many others have their transport across the inner membrane regulated?A) Regulated transport allows for more effective substrate cycling.
B) Ultimately all electrons flow into the electron-transport chain, which regulates electron flow from the matrix to the inner membrane space.
C) The experiment where bacteriorhodopsin and ATP synthase were inserted into reconstituted vesicles showed that biochemically, membranes control the movement of electrons in the respiratory chain.
D) Many of the reactions in the citric acid cycle and ATP synthesis are driven by accessibility of substrates and differential gradients across the inner membrane.
E) It is necessary to segregate the enzymes capable of substrate level phosphorylation during anaerobic respiration.