※<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
※ 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 ※ 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
10. The reaction catalyzed by the pyruvate dehydrogenase complex can be divided all of the following stages except on C. ac D. regeneration of cofactors E. all are stages in the reaction 11. Which of the following statements is correct about lactate A. it is the dead end product of anaerobic respiration in the muscle and liver B. it is transported from the muscle to the liver where it enters glycolysis C. it is transported from the liver to the muscle where it enters the citric acid cycle D. it is transported from the muscle to the liver where it is converted to glucose via gluconeogeneSIs 12 Animals can't catalyze the net conversion of acetyl CoA into carbohydrates because A synthesis pathways occur in the cytosol while the degradation pathways that occur in the mitochondria B there is a net lose of two molecules of co2 in the citric acid cycle C acetyl co a can not be converted to oxaloacetate D. there are no metabolic pathways that connect pathways that form acetyl CoA with those that form carbohydrates 13. Germinating plant seeds can covert acetyl CoA into carbohydrates whereas animals are incapable of converting fatty acids into glucose. This difference is because A animals have glycogen and don't need to make glucose from fatty acids B. plants use the glyoxylate cycle to convert two moles of acety I Co A into L-malate which is converted into a precursor for gluconeogenesis. Animals do not have the glyoxylate cycle C. plants can carry out photosynthesis which make the conversion of acetyl Co A into gluconeogensis precursors D Both plants and animals have the glyoxylate cycle, but animals do not have a mechanism to convert L-malate into the precursors for gluconeogensis 14. Which of the following enzymes found in the citric acid cycle is a membrane bound protein? B Succinate dehydrogenase C Succinyl CoA Synthetase D Malate dehydrogenase 15. Which of the following is not correct conceming the isomerization of citrate to isocitrate A. the enzyme contains a unique Fe-s cluster
10.The reaction catalyzed by the pyruvate dehydrogenase complex can be divided all of the following stages except: A. Decarboxylation B. Oxidation C. Activation D. regeneration of cofactors E. all are stages in the reaction 11. Which of the following statements is correct about lactate A. it is the dead end product of anaerobic respiration in the muscle and liver B. it is transported from the muscle to the liver where it enters glycolysis C. it is transported from the liver to the muscle where it enters the citric acid cycle D. it is transported from the muscle to the liver where it is converted to glucose via gluconeogenesis 12. Animals can’t catalyze the net conversion of acetyl CoA into carbohydrates because A. synthesis pathways occur in the cytosol while the degradation pathways that occur in the mitochondria B. there is a net lose of two molecules of CO2 in the citric acid cycle C. acetyl CoA can not be converted to oxaloacetate D. there are no metabolic pathways that connect pathways that form acetyl CoA with those that form carbohydrates. 13. Germinating plant seeds can covert acetyl CoA into carbohydrates, whereas animals are incapable of converting fatty acids into glucose. This difference is because: A. animals have glycogen and don’t need to make glucose from fatty acids. B. plants use the glyoxylate cycle to convert two moles of acety l Co A into L-malate which is converted into a precursor for gluconeogenesis. Animals do not have the glyoxylate cycle. C. plants can carry out photosynthesis which make the conversion of acetyl Co A into gluconeogensis precursors possible D. Both plants and animals have the glyoxylate cycle, but animals do not have a mechanism to convert L-malate into the precursors for gluconeogensis 14. Which of the following enzymes found in the citric acid cycle is a membrane bound protein? A. Aconitase B. Succinate dehydrogenase C. Succinyl CoA Synthetase D. Malate dehydrogenase 15. Which of the following is not correct concerning the isomerization of citrate to isocitrate: A. the enzyme contains a unique Fe-S cluster
B. converts a tertiary alcohol which can not be oxidized)to a secondary C. it is a major control step in the citric acid cycle 16. The two main purposes of the citric acid cycle are A synthesis of citrate and gluconeogenesis B degrad ation of acetyl Co a to produce energy and supply of precursors for biomolecules C degradation of pyruvate to produce energy and supply of precursors for D degradation of acetyl Co a to produce energy and gluconeogenesis 17. Gluconeogenesis takes place predominantly in the B. bra C. heart D E liver 18. Biotin functions as a: B carrier of activated carbon dioxide C. carrier of activated electrons D. carrier of activated acyl groups 19. What are the most important products that cells generate by means of th sphate p C NADP+ and ribose-5-phosphate D NADPH and UDP-nibe E. ribulose-1, 5-bisphosphate and NADPH 20. Which combination of cofactors is involved in the conversion of pyruvate to acetyl-CoA? A NAD+. biotin and tpP. and Co a B TPP, Co A, lipoic acid, AD C pyridoxal phosphate, FAD and lipoic acid biotin fad. and Tp E. biotin nad+ and FAd 21. In a eukaryotic cell, the enzymes of glycolysis are located in the and the enzymes of the tCa cycle are located in the
B. converts a tertiary alcohol ( which can not be oxidized) to a secondary alcohol that can be oxidized C. it is a major control step in the citric acid cycle D. all are correct 16. The two main purposes of the citric acid cycle are: A. synthesis of citrate and gluconeogenesis B. degradation of acetyl Co A to produce energy and supply of precursors for biomolecules C. degradation of pyruvate to produce energy and supply of precursors for biomolecules D. degradation of acetyl Co A to produce energy and gluconeogenesis 17. Gluconeogenesis takes place predominantly in the A. muscles B. brain C. heart D. pancrease E. liver 18. Biotin functions as a: A. carrier of activated aldehydes B. carrier of activated carbon dioxide C. carrier of activated electrons D. carrier of activated acyl groups 19. What are the most important products that cells generate by means of the pentose phosphate pathway? A. lactate and ATP B. ribose-5-phosphate and NADPH C. NADP+ and ribose-5-phosphate D. NADPH and UDP-ribose E. ribulose-1,5-bisphosphate and NADPH 20. Which combination of cofactors is involved in the conversion of pyruvate to acetyl-CoA? A. NAD+, biotin, and TPP, and Co A B. TPP, Co A, lipoic acid, NAD+ and FAD C. pyridoxal phosphate, FAD and lipoic acid, D. biotin, FAD, and TPP E. biotin, NAD+, and FAD 21. In a eukaryotic cell, the enzymes of glycolysis are located in the ____ and the enzymes of the TCA cycle are located in the ____: A plasma membrane, cytosol
B cytosol, mitochondrial matrix. C cytosol, mitochondrial matrix and membrane D nucleus, cytosol 22. Which of the following compound is responsible for coordinated regulation of glycolysis and gluconeogenesis? A NADH b acetyl-COA c fructose 2, 6 bis phosphate d fructose 1, 6 bis phosphate 23. A lack of phosphoglucomutase activ ity is most likely to produce a A pyruvate B ribose 5-phosphate C NADP D NADH E glycoge 24. Approximately 10% of the glucose derived from glycogen and released from the liver during fasting is produced directly(not generated via the action of glucose-6-phosphatase) by which of the following enzymes? B Debranching enzyme C Branching enzyme D Glycogen synthase E UTP/glucose 1-phosphate pyrophosphorylase 25. Which if the following enzymes forms alpha-1, 6 linkages in glycogen? B glycogen branching enzyme C. amy lo-(1, 6)glucosidase D phosphorylase kinase E glucose 6-phosphatase 26. Which enzyme is present in the liver but NOT in the muscle? A. hexokil C lactate dehydrogenase D pyruvate dehydrogenase E glycogen phosphory lase 27 Gluconeogenesis from lactate does not require activ ity of A aldolase
B cytosol, mitochondrial matrix. C cytosol, mitochondrial matrix and membrane. D nucleus, cytosol. 22. Which of the following compound is responsible for coordinated regulation of glycolysis and gluconeogenesis? A NADH B acetyl-CoA C fructose 2,6 bis phosphate D fructose 1,6 bis phosphate 23.A lack of phosphoglucomutase activity is most likely to produce a deficiency of A. pyruvate B. ribose 5-phosphate C. NADP D. NADH E. glycogen 24. Approximately 10% of the glucose derived from glycogen and released from the liver during fasting is produced directly (not generated via the action of glucose-6-phosphatase) by which of the following enzymes? A. Glycogen phosphorylase B. Debranching enzyme C. Branching enzyme D. Glycogen synthase E. UTP/glucose 1-phosphate pyrophosphorylase 25. Which if the following enzymes forms alpha-1, 6 linkages in glycogen? A. glycogen phosphorylase B. glycogen branching enzyme C. amylo-(1,6) glucosidase D. phosphorylase kinase E. glucose 6-phosphatase 26. Which enzyme is present in the liver but NOT in the muscle? A. hexokinase B. glucose 6-phosphatase C. lactate dehydrogenase D. pyruvate dehydrogenase E. glycogen phosphorylase 27. Gluconeogenesis from lactate does not require activity of A. aldolase
B phosphofructokinase C glyceraldehyde 3-phosphate dehydrogenase D triose phosphate isomerase E phosphoglycerate kinase 28 Which compound does noT contribute to the net formation of glucose A propionate B glycerol C acetyl-CoA D. lactate E alanine 29. Which of the following describes the mechanism by which NADH generated in the cytoplasm donates electrons to oxy gen via the mitochondrial electron transport system? A. A specific transport system enables Nadh to pass through the mitochondrial B NADH reduces cytoplasmic FAd to FADH2, which passes through the mitochondrial membrane C NADH reduces cy toplasmic dihyroxyacetone phosphate to glycer phosphate, which is reoxidized by an enzyme associated with the mitochondrial electron transport system D NADH reduces cytoplasmic NADP to NADPH, which can enter the mitochon E. None of the above mechanism is used 30. Mammals cannot achieve a NET synthesis of glucose from fatty acids due to the inability to convert A acetyl-Coa to acetoacetat B acetyl-Coa to pyruvate C oxaloacetate to pyruvate D acetyl-Coa to malonyl CoA E. methylmalonyl-CoA to succinyl-CoA 31. The immediate products of oxidation of one mole of glucose 6-phosphate through the oxidative portion of the pentose phosphate pathway are A one mole of ribulose 5-phosphate, one mole of CO2 and two moles of B one mole of ribulose 5-phosphate, one mole of Co2 and two moles of NADPH C. one mole of xylulose 5-phosphate, one mole of CO2 and two moles of NADPH
B. phosphofructokinase C. glyceraldehyde 3-phosphate dehydrogenase D triose phosphate isomerase E. phosphoglycerate kinase 28. Which compound does NOT contribute to the net formation of glucose during gluconeogenesis in humans? A. propionate B. glycerol C. acetyl-CoA D. lactate E. alanine 29. Which of the following describes the mechanism by which NADH generated in the cytoplasm donates electrons to oxygen via the mitochondrial electron transport system? A. A specific transport system enables NADH to pass through the mitochondrial membrane. B. NADH reduces cytoplasmic FAD to FADH2, which passes through the mitochondrial membrane. C. NADH reduces cytoplasmic dihyroxyacetone phosphate to glycerol phosphate, which is reoxidized by an enzyme associated with the mitochondrial electron transport system. D. NADH reduces cytoplasmic NADP to NADPH, which can enter the mitochondria. E. None of the above mechanism is used. 30. Mammals cannot achieve a NET synthesis of glucose from fatty acids due to the inability to convert A. acetyl-CoA to acetoacetate. B. acetyl-CoA to pyruvate. C. oxaloacetate to pyruvate. D. acetyl-CoA to malonyl CoA. E. methylmalonyl-CoA to succinyl-CoA. 31. The immediate products of oxidation of one mole of glucose 6-phosphate through the oxidative portion of the pentose phosphate pathway are: A. one mole of ribulose 5-phosphate, one mole of CO2 and two moles of NAD. B. one mole of ribulose 5-phosphate, one mole of CO2 and two moles of NADPH. C. one mole of xylulose 5-phosphate, one mole of CO2 and two moles of NADPH
D one mole of ribose 5-phosphate, one mole ofCO2 and two moles of NADPH F. one mole of fructose 6-phosphate and two moles of NADP 32. The enzyme transketolase is a component of A the TCa cycle B the pentose pathway C. fatty acid synthase D the pyruvate dehydrogenase complex E. none of the above 33. Glycolysis A. Takes place in the mitochondrion B. Is the major provider of ATP to muscle during heavy exercise C. Is controlled by levels of fructose-2, 6 bis phosphate D. Is the only pathway known from glucose to pyruvate 34. Glycogen phosphory lase A. Responds oppositely to epinephrine in liver and muscle B. Is phosphory lated by protein kinase A C. Has an R and T form that are stabilized by AMP and ATP respectively D. Is phosphory lated in response to cyclic AMP and Ca2+ 35. The citric acid cycle A. Oxidizes acetate to co, and water B. Provides intermediates for amino acid, porphyrin and carbohy drate C. Can accomplish net synthesis of succinate from acetylCoA D. Can be replenished by carboxylation of PEP 36. Which one of the following statements about gluconeogenesis in animal cells is true? a the conversion of glucose-6-phosphate to glucose is catalyzed by b the conversion of phosphoenol pyruvate to 2-phosphoglycerate occurs in two steps, including a carboxylat c the conversion of fructose-1, 6-bisphosphate to fructose-6-phosphate is not catalyzed by phosphofructokinase the enzyme involved in d an animal fed a large excess of fat in the diet will convert any fat not needed for energy e production into glycogen for later u f gluconeogenesis helps to reduce blood glucose after a
D. one mole of ribose 5-phosphate, one mole of CO2 and two moles of NADPH. F. one mole of fructose 6-phosphate and two moles of NADP. 32. The enzyme transketolase is a component of A. the TCA cycle. B. the pentose pathway. C. fatty acid synthase. D. the pyruvate dehydrogenase complex. E. none of the above 33. Glycolysis A. Takes place in the mitochondrion B. Is the major provider of ATP to muscle during heavy exercise C. Is controlled by levels of fructose-2,6 bis phosphate D. Is the only pathway known from glucose to pyruvate 34. Glycogen phosphorylase A. Responds oppositely to epinephrine in liver and muscle B. Is phosphorylated by protein kinase A C. Has an R and T form that are stabilized by AMP and ATP, respectively D. Is phosphorylated in response to cyclic AMP and Ca2+ 35. The citric acid cycle A. Oxidizes acetate to CO2 and water B. Provides intermediates for amino acid, porphyrin and carbohydrate biosynthesis C. Can accomplish net synthesis of succinate from acetylCoA D. Can be replenished by carboxylation of PEP 36. Which one of the following statements about gluconeogenesis in animal cells is true? A the conversion of glucose-6-phosphate to glucose is catalyzed by hexokinase. B the conversion of phosphoenolpyruvate to 2-phosphoglycerate occurs in two steps, including a carboxylation. C the conversion of fructose-1,6-bisphosphate to fructose-6-phosphate is not catalyzed by phosphofructokinase, the enzyme involved in glycolysis. D an animal fed a large excess of fat in the diet will convert any fat not needed for energy E production into glycogen for later use. F gluconeogenesis helps to reduce blood glucose after a