※<19 1. Choose the correct path taken by a pair of electrons as it travels down the electron transport chain NADH→ complex I→ complex‖l Q→ complexⅢl→cyt C→ complex N→O FADH2→ complex I→CoQ→ complexⅢl→cytc→ complex →0 C NADH→ complex Il→oytC→ complex Il→CoQ→ complex D NADH→ complex I→CoQ→ complex‖→cytc→ complex 2. In the binding- change mechanism for ATP synthase. A every proton that is translocated causes the formation of 1 ATP B ADP and Pi bind to the a-B protomer in the L conformation c AtP binds to the a-B protomer in the o conformation D All three a-B protomers cycle through the same conformation at the same time 3. Which of the electron transport complexes are responsiblefor translocating protons into the intermembrane space? A Complex I, II, Ill, and M. B Complex I,l,andⅣ. c Complex lI and cytochrome c D Complex I, I, N and V E Complex I and IV 4. Which of the following is not correct conceming the uncoupling of electron transport from oxidative phosphorylation a uncoupling slows all aerobic metabolic activities B uncoupling slows the citric acid cycle c stops electron transport D ps ATP synthe 5. Which of the following is not a redox center in the electron transport chain? A FMN b Fe-s clusters D cytochromes E hemoglobin 6. The pH in the mitochondrial matri than the pH in the
※<19> 1. Choose the correct path taken by a pair of electrons as it travels down the electron transport chain: A NADH → complex I → complex II → Co Q → complex III → Cyt C → complex IV → O2 B FADH2 →complex I →Co Q → complex III → Cyt C → complex IV → O2 C NADH →complex II →Cyt C → complex III → Co Q → complex IV → O2 D NADH →complex I → Co Q → complex III → Cyt C → complex IV → O2 2. In the binding-change mechanism for ATP synthase, A every proton that is translocated causes the formation of 1 ATP B ADP and Pi bind to the - protomer in the L conformation. C ATP binds to the - protomer in the O conformation D All three - protomers cycle through the same conformation at the same time 3. Which of the electron transport complexes are responsible for translocating protons into the intermembrane space? A Complex I, II, III, and IV. B Complex I, III, and IV. C Complex II and cytochrome c D Complex I, III, IV and V E Complex I and IV. 4. Which of the following is not correct concerning the uncoupling of electron transport from oxidative phosphorylation: A uncoupling slows all aerobic metabolic activities. B uncoupling slows the citric acid cycle C stops electron transport D stops ATP synthesis. 5. Which of the following is not a redox center in the electron transport chain? A FMN B Fe-S clusters C Co Q D cytochromes E hemoglobin 6. The pH in the mitochondrial matrix is ___ than the pH in the intermembrane space
1) lower 2) highe 7. The mitochon rial matrix pre b Is basic relative to the cytoplasm of the cell c Is the location of the enzymes of fatty acid biosynthesis d Is separated from the cytoplasm by two membranes 8. The electron transport chain a Has components with mostly more positive electrode potentials going from NADH to O2 B Has both 2 and l electron cariers c Is a strictly lin ar unt ached pa emember succinat dehydrogenase) 9. The bc I complex(complex Ill) a Has a f1 b Sends the two electrons from reduced quinone on separate pathways c Oxidizes quinol on one side of the membrane and reduces it on the d Is an important part of all bacterial electron transport chains 10. Coupling between electron transport and ATP synthesis a Provides the control by which oxidation rates are governed by ATP utilization b Is eliminated by uncouplers which inhibit the ATP synthase(I eliminated, but uncouplers don't inhibit ATP synthase) c Is always tight in animal mitochondria under physiological conditions(remember brown fat and thermogenesis) d Is eliminated by lipid-soluble weak acids I 1. Mitochondrial electron transport a Is accomplished by both electron and hydride movements B Proceeds in the absence of ATP synthesis c Is accompanied by movements of protons across the membrane d Can start with a variety of substrates, such as lactate, formate glycerol-3P, succinate and NADH 12. Uncoupling of mitochondrial oxidative phosphorylation a halts all mitochondrial metabolism b slows down the citric acid cycle C allows continued mitochondrial ATP formation, but halts 02
1) lower 2) higher 7. The mitochondrial matrix A Is a dilute solution of protein (about 50% protein) B Is basic relative to the cytoplasm of the cell C Is the location of the enzymes of fatty acid biosynthesis D Is separated from the cytoplasm by two membranes 8. The electron transport chain A Has components with mostly more positive electrode potentials going from NADH to O2 B Has both 2 and 1 electron carriers C Is a strictly linear, unbranched pathway (remember succinate dehydrogenase) 9. The bc1 complex (complex III) A Has a flavin B Sends the two electrons from reduced quinone on separate pathways C Oxidizes quinol on one side of the membrane and reduces it on the other D Is an important part of all bacterial electron transport chains 10. Coupling between electron transport and ATP synthesis A Provides the control by which oxidation rates are governed by ATP utilization B Is eliminated by uncouplers which inhibit the ATP synthase (Is eliminated, but uncouplers don’t inhibit ATP synthase) C Is always tight in animal mitochondria under physiological conditions (remember brown fat and thermogenesis) D Is eliminated by lipid-soluble weak acids 11. Mitochondrial electron transport A Is accomplished by both electron and hydride movements B Proceeds in the absence of ATP synthesis C Is accompanied by movements of protons across the membrane D Can start with a variety of substrates, such as lactate, formate, glycerol-3P, succinate and NADH 12.Uncoupling of mitochondrial oxidative phosphorylation: A halts all mitochondrial metabolism. B slows down the citric acid cycle. C allows continued mitochondrial ATP formation, but halts O2 consumption
d halts mitochondrial ATP formation, but allows continued 02 E none of the above 13. Which of the following statements about the chemiosmotic theory is correct? a Electron transfer in mitochondria is accompanied by a release of protons on one side of the inner mitochondrial membrane b The effect of uncoupling reagents is a consequence of their ability to carry electrons through membranes C Although energy transductions in mitochondria and in chloroplasts are superficially similar, they have fundamentally different mechanisms d The membrane ATPsynthase, which plays an important role in other hypotheses for energy coupling, has no significant role in the chemiosmotic theory E All of the above statements are correct 14. The rate of flow of electrons through the electron-transport chain is regulated by a the atp AdP ratio c the rate of oxidative phosphorylation. d feedback inhibition by H20 e the catalytic rate of cytochrome oxidase 15. Which of the following experimental observations would not support the chemiosmotic model of oxidative phosphorylation? a If mitochondrial membranes are ruptured, oxidative phosphorylation cannot occur b Raising the ph of the fluid in the intermembrane space results in ATP synthesis in the matrix c Transfer of electrons through the respiratory chain results in formation of a proton gradient across the inner mitochondrial d The orientation of the enzyme complexes of the electron transfer chain results in a unidirectional flow ofh e Radioactively labeled inorganic phosphate is incorporated into cytosolic AtP only in the presence of an H* gradient across the inner mitochondrial membrane 16. Indicate whether each of the following statements about the mitochondrial electron transfer chain and oxidative phosphorylation is true (T)or false(F)
D halts mitochondrial ATP formation, but allows continued O2 consumption. E none of the above. 13. Which of the following statements about the chemiosmotic theory is correct? A Electron transfer in mitochondria is accompanied by a release of protons on one side of the inner mitochondrial membrane. B The effect of uncoupling reagents is a consequence of their ability to carry electrons through membranes. C Although energy transductions in mitochondria and in chloroplasts are superficially similar, they have fundamentally different mechanisms. D The membrane ATPsynthase, which plays an important role in other hypotheses for energy coupling, has no significant role in the chemiosmotic theory. E All of the above statements are correct. 14. The rate of flow of electrons through the electron-transport chain is regulated by A the ATP:ADP ratio. B the concentration of acetyl CoA. C the rate of oxidative phosphorylation. D feedback inhibition by H2O. E the catalytic rate of cytochrome oxidase. 15. Which of the following experimental observations would not support the chemiosmotic model of oxidative phosphorylation? A If mitochondrial membranes are ruptured, oxidative phosphorylation cannot occur. B Raising the pH of the fluid in the intermembrane space results in ATP synthesis in the matrix. C Transfer of electrons through the respiratory chain results in formation of a proton gradient across the inner mitochondrial membrane. D The orientation of the enzyme complexes of the electron transfer chain results in a unidirectional flow of H+ . E Radioactively labeled inorganic phosphate is incorporated into cytosolic ATP only in the presence of an H+ gradient across the inner mitochondrial membrane. 16.Indicate whether each of the following statements about the mitochondrial electron transfer chain and oxidative phosphorylation is true (T) or false (F)
a NADH dehy drogenase complex, cytochrome bc, complex, and cytochrome oxidase all are transmembrane proteins b Synthesized ATP must be transported into the intermembrane space before it can enter the cytos c Cytochrome c and the Fi part of ATPase are peripheral membrane protein D Complexes I, Il, Ill, and IV all are proton pumps e Ubiquinone is a hydrophilic molecule f Ubiquinone and the fo part of ATP synthase are both peripheral membrane proteins G The final electron acceptor is H,O 17. In order to examine the citric acid cycle you have obtained a pure preparation of isolated, intact mitochondria. You add some succinyl-CoA to the suspension of mitochondria. How many moles of ATP would you expect to be generated in one turn of the citric acid cycle from each mole of ccinyl-CoA added to the test tube? 1)3 2)4 3) 4)5.5 5)No ATP would form under these conditions 1. A patient has sporadic bouts of fainting that are found to correlate with hypoglycemic ailment in the patients family. The most likely explanation is a defect in A GLUT4 transporter B insulin receptor c liver glycogen synthase D muscle glycogen phosphory lase(e) muscle 6-phosphofructo-1-kinase 2. Glucose uptake by skeletal muscle is increased by exercise because of an increase in the intracellular concentration of A AMI B ADP C ATP creatine phospha E NADH 3. Relative to the well-fed state. which of the following is increased in the liver in the starved state? a AMP concentration B Fructose-2, 6-bisphosphatase activi c Pyruvate dehydrogenase activity
A NADH dehydrogenase complex, cytochrome bc1 complex, and cytochrome oxidase all are transmembrane proteins. B Synthesized ATP must be transported into the intermembrane space before it can enter the cytosol. C Cytochrome c and the F1 part of ATPase are peripheral membrane protein. D Complexes I, II, III, and IV all are proton pumps. E Ubiquinone is a hydrophilic molecule. F Ubiquinone and the Fo part of ATP synthase are both peripheral membrane proteins. G The final electron acceptor is H2O. 17. In order to examine the citric acid cycle you have obtained a pure preparation of isolated, intact mitochondria. You add some succinyl-CoA to the suspension of mitochondria. How many moles of ATP would you expect to be generated in one turn of the citric acid cycle from each mole of succinyl-CoA added to the test tube? 1) 3 2) 4 3) 5 4) 5.5 5) No ATP would form under these conditions. 5 ※<20> 1. A patient has sporadic bouts of fainting that are found to correlate with hypoglycemic episodes. The hypoglycemia is easily cured by ingestion of food. There is a history of this ailment in the patient's family. The most likely explanation is a defect in A GLUT4 transporter B insulin receptor C liver glycogen synthase D muscle glycogen phosphorylase(e) muscle 6-phosphofructo-1-kinase 2. Glucose uptake by skeletal muscle is increased by exercise because of an increase in the intracellular concentration of A AMP B ADP C ATP D creatine phosphate E NADH 3. Relative to the well-fed state, which of the following is increased in the liver in the starved state? A AMP concentration B Fructose-2,6-bisphosphatase activity C Pyruvate dehydrogenase activity
D Pyruvate kinase activity 4. The synthesis of glycogen, starch and lactose A. uses glucose-1-phosphate as the only substrate B. uses a sugar nucleotide as a substrate C. only takes place in the liver of mammals D. involves the addition of a sugar residue at the reducing end of the a growing polymer 5. An enzyme used in both glycolysis and gluconeogensis is A hexokinase C phosphoglycerate kinase D pyruvate carboxylase E. phosphofructokinase 6. One cycle of the citric acid cycle produces moles of nadh moles of fad and moles of gtp B.4;2;1 D.2;2;2 7. Which list of intermediates is in the correct order for the part of citric acid cycle that includes these intermediates? A lyl-CoA, succinate, a-ketoglutarate, fumarate, malat B a-ketoglutarate, succinyl-CoA, succinate, fumarate, C succinate, succinyl-CoA, fumarate, a-ketoglutarate, D a-ketoglutarate, succinyl-CoA, succinate, malate, fumarate E a-ketoglutarate, malate, fumarate, succinyl-CoA, succinate 8. In glycolysis, substrate level phosphorylation is catalyzed by A hexokinase B glyceraldehyde 3-phosphate dehydrogena D phosphoglycerate kinase 9. The first step of gluconeogensis is catalyzed by B pyruvate carboxylase C. PEP carboxykinase D. pyruvate kinase
D Pyruvate kinase activity 4. The synthesis of glycogen, starch and lactose A. uses glucose-1-phosphate as the only substrate. B. uses a sugar nucleotide as a substrate. C. only takes place in the liver of mammals. D. involves the addition of a sugar residue at the reducing end of the a growing polymer. 5. An enzyme used in both glycolysis and gluconeogensis is: A. hexokinase B. glucose-6-phosphatase C. phosphoglycerate kinase D. pyruvate carboxylase E. phosphofructokinase 6. One cycle of the citric acid cycle produces ______ moles of NADH, _____ moles of FADH2 and _____ moles of GTP : A. 3; 2; 0 B. 4; 2; 1 C. 3; 1; 1 D. 2; 2; 2 7. Which list of intermediates is in the correct order for the part of citric acid cycle that includes these intermediates? A. succinyl-CoA, succinate, -ketoglutarate, fumarate, malate B. -ketoglutarate, succinyl-CoA, succinate, fumarate, malate C. succinate, succinyl-CoA, fumarate, -ketoglutarate, malate D. -ketoglutarate, succinyl-CoA, succinate, malate, fumarate E. -ketoglutarate, malate, fumarate, succinyl-CoA, succinate 8. In glycolysis, substrate level phosphorylation is catalyzed by: A. hexokinase B. glyceraldehyde 3-phosphate dehydrogenase C. phosphofructokinase D. phosphoglycerate kinase 9. The first step of gluconeogensis is catalyzed by: A. hexokinase B. pyruvate carboxylase C. PEP carboxykinase D. pyruvate kinase