1. Metabolism is best defined as a collection of
a. biochemical reactions that convert chemical energy into work.
b. biochemical reactions that convert mechanical energy into work.
c. enzymes that convert glucose into carbon dioxide.
d. enzymes that conve
ANS: A DIF: Easy REF: 9.1
OBJ: 9.1.a. List the major metabolic pathways in animals. MSC: Remembering
2. Catabolic pathways are always paired with anabolic pathways. Why?
a. Catabolic pathways build up new molecules and anabolic break down molecules.
b. Catabolic pathways break down molecules and anabolic build up new molecules.
c. Both require ATP to ope
ANS: A DIF: Medium REF: 9.1
OBJ: 9.1.c. Distinguish between catabolic pathways and anabolic pathways.
MSC: Analyzing
3. What may be the root cause of the slowing of the flux of metabolites through the glycolysis
and gluconeogenesis pathways in your body?
a. elevated levels of amino acids in the body
b. elevated levels of glycogen in the body
c. lowered levels of protein
ANS: D DIF: Medium REF: 9.1
OBJ: 9.1.d. Explain how flux through a pathway changes in response to substrate
concentration and enzyme activity. MSC: Evaluating
4. Flux is defined as the rate at which __________ is/are interconverted.
a. enzymes
b. metabolites
c. sugars
d. energy
ANS: B DIF: Easy REF: 9.1
OBJ: 9.1.e. Define metabolic flux. MSC: Remembering
5. In the reaction A? B, if at equilibrium [B] >> [A], what can be said about the directionality of
the reaction?
a. strongly favored in the forward direction
b. strongly favored in the reverse direction
c. strongly favored in both directions
d. Not enoug
ANS: A DIF: Medium REF: 9.1
OBJ: 9.1.d. Explain how flux through a pathway changes in response to substrate
concentration and enzyme activity. MSC: Applying
6. For the following reaction A? B, if at equilibrium ?DG�? > 0, what can be said about the
directionality of the reaction?
a. strongly favored in the forward direction
b. strongly favored in the reverse direction
c. strongly favored in both directions
d.
ANS: B DIF: Medium REF: 9.1
OBJ: 9.1.d. Explain how flux through a pathway changes in response to substrate
concentration and enzyme activity. MSC: Applying
7. How can an unfavorable reaction (?G�? > 0) still occur in a metabolic pathway?
a. Link it to another unfavorable reaction.
b. Link it to a favorable reaction.
c. They cannot be used in metabolic pathway reactions.
d. Increase the temperature of the rea
ANS: B DIF: Easy REF: 9.1
OBJ: 9.1.g. Explain how reaction coupling allows an unfavorable ?G value to be part of a
metabolic pathway. MSC: Understanding
8. Which of the following metabolic pathways is only found in plants?
a. glycolysis
b. citrate cycle
c. photosynthesis
d. urea cycle
ANS: C DIF: Easy REF: 9.1
OBJ: 9.1.b. List the major metabolic pathways in plants. MSC: Remembering
9. Which of the following pathways are found in both plants and animals?
a. photosynthesis and carbon fixation
b. urea cycle
c. nitrogen fixation
d. citrate cycle
ANS: D DIF: Easy REF: 9.1
OBJ: 9.1.b. List the major metabolic pathways in plants. MSC: Remembering
13. Which of the following is an energy conversion pathway?
a. urea cycle
b. citrate cycle
c. nitrogen fixation and assimilation
d. fatty acid degradation and synthesis
ANS: B DIF: Easy REF: 9.1
OBJ: 9.1.f. Distinguish between energy conversion pathways and metabolite synthesis and
degradation pathways. MSC: Understanding
14. What is the main difference between energy conversion pathways and metabolite synthesis
pathways?
a. Energy conversion pathways produce ATP.
b. Energy conversion pathways deplete ATP.
c. Metabolite synthesis pathway uses ATP to break down metabolites.
ANS: A DIF: Easy REF: 9.1
OBJ: 9.1.f. Distinguish between energy conversion pathways and metabolite synthesis and
degradation pathways. MSC: Understanding
15. A shared intermediate can be defined as a molecule that is
a. a reactant in a pathway.
b. the final product of a pathway.
c. the final product of a pathway and the reactant of the next
pathway.
d. favorable to produce.
ANS: C DIF: Easy REF: 9.1
OBJ: 9.1.h. Define shared intermediate. MSC: Remembering
17. Which of the following is the correct formula for glucose?
a. C12H22O11
b. C6H12O6
c. C6H6O6
d. C14N2H18O5
ANS: B DIF: Easy REF: 9.2
OBJ: 9.2.a. Distinguish between glucose and fructose. MSC: Remembering
18. Compare the structure of an aldose to a ketose.
a. Ketose has a carbon backbone with an aldehyde group at the end of the molecule,
whereas aldose has a ketone group at the end of the molecule.
b. Ketose has a carbon backbone with a ketone group at the
ANS: D DIF: Medium REF: 9.2
OBJ: 9.2.c. Define aldose and ketose. MSC: Analyzing
19. A chiral center is an atom with
a. two different functional groups and a strong dipole.
b. four different functional groups and which lacks a plane of symmetry.
c. all the same functional groups and a plane of symmetry.
d. the ability to hydrogen bond
ANS: B DIF: Easy REF: 9.2 OBJ: 9.2.d. Define chiral
center.
MSC: Applying
20. Glucose and fructose are both C6H12O6. What is the structural difference between them?
a. Glucose is a five-membered ring and fructose is a six-membered ring.
b. Fructose is a five-membered ring and glucose is a six-membered ring.
c. Glucose is a line
ANS: B DIF: Easy REF: 9.2
OBJ: 9.2.a. Distinguish between glucose and fructose. MSC: Applying
21. Explain the difference between a Fisher projection and a Haworth projection.
a. Fischer projections illustrate the cyclic form, whereas Haworth projections represent
the linear form.
b. The Haworth projection illustrates the six-membered rings, wherea
ANS: C DIF: Medium REF: 9.2
OBJ: 9.2.b. Explain the difference between a Haworth projection and a Fisher projection.
MSC: Applying
22. Define aldose.
a. Only aldose molecules have CH2OH.
b. Aldose molecules have ketone functional groups.
c. Aldose molecules have aldehyde functional groups.
d. Aldose molecules are all five-membered rings.
ANS: C DIF: Easy REF: 9.2
OBJ: 9.2.c. Define aldose and ketose. MSC: Remembering
23. Define ketose.
a. Only ketose molecules have CH2OH.
b. Ketose molecules have ketone functional groups.
c. Ketose molecules have aldehyde functional groups.
d. Ketose molecules are all five-membered rings.
ANS: B DIF: Easy REF: 9.2
OBJ: 9.2.c. Define aldose and ketose. MSC: Remembering
24. Distinguish between D and L isomers.
a. D is right handed and L is left handed.
b. D is left handed and L is right handed.
c. D and L only differ in the position of one chiral center.
d. D is the boat conformation and L is the chair conformation.
ANS: A DIF: Easy REF: 9.2
OBJ: 9.2.e. Distinguish between D and L isomers. MSC: Understanding
26. Anomers differ from each other by changes at the __________ carbon.
a. chiral
b. C-2
c. C-3
d. C-1
ANS: D DIF: Medium REF: 9.2
OBJ: 9.2.f. Differentiate among epimers, anomers, and isomers.
MSC: Understanding
27. Which of following is an anomeric pair?
a. D-glucose and D-fructose
b. D-glucose and L-fructose
c. D-glucose and L-glucose
d. ?-D-glucose and ?-D-glucose
ANS: D DIF: Medium REF: 9.2
OBJ: 9.2.f. Differentiate among epimers, anomers, and isomers.
MSC: Understanding
28. During the cyclization of D-glucose, where is a new chiral center formed?
a. C-1
b. C-3
c. C-4
d. C-5
ANS: A DIF: Easy REF: 9.2
OBJ: 9.2.g. Demonstrate the cyclization of linear glucose to cyclic glucopyranose.
MSC: Understanding
29. The test using copper to determine blood glucose levels is called a __________ test.
a. glycolysis
b. phosphorylation
c. Benedict's
d. McKee's
ANS: C DIF: Easy REF: 9.2
OBJ: 9.2.h. Explain the significance of Benedict's test. MSC: Remembering
30. A carbohydrate that reacts with oxidizing agents such as Cu+2 is called a(n) __________
sugar.
a. oxidizing
b. reducing
c. rentose
d. aldose
ANS: B DIF: Medium REF: 9.2
OBJ: 9.2.i. Differentiate between a reducing and a nonreducing sugar.
MSC: Remembering
31. Sucrose is a nonreducing sugar. Why?
a. Sucrose does not contain an aldehyde functional group.
b. Sucrose does not react with heat.
c. Sucrose is a pyranose that cannot be reacted with copper.
d. Sucrose is a disaccharide that cannot be converted to a
ANS: D DIF: Medium REF: 9.2
OBJ: 9.2.i. Differentiate between a reducing and a nonreducing sugar.
MSC: Understanding
34. The glycolytic pathway is responsible for passing molecules to which other pathways?
a. citrate cycle and nitrogen fixation
b. photosynthesis and oxidative phosphorylation
c. citrate cycle and oxidative phosphorylation
d. urea cycle and fatty acid syn
ANS: C DIF: Easy REF: 9.3
OBJ: 9.3.a. Describe the glycolytic pathway. MSC: Understanding
35. Which of the following is NOT a reason why glycolysis is considered one of the core
metabolic pathways in nature?
a. Glycolytic enzymes are hugely conserved among all living organisms.
b. It is a primary pathway for ATP generation under anaerobic cond
ANS: D DIF: Easy REF: 9.3
OBJ: 9.3.b. List the three primary reasons why glycolysis is considered one of the core
metabolic pathways in nature. MSC: Understanding
36. Which of the following is the correct net reaction for glycolysis?
a. glucose + 2 ATP ? 2 lactate + 2 ADP + 2 Pi
b. glucose + 2 ADP + 2 Pi + 2 NAD+ ? 2 pyruvate + 2 ATP + 2 NADH + 4 H+
c. glucose + 2 ADP + 2 Pi ? 2 CH3CH2OH + 2 CO2 + 2 ATP
d. glucose
ANS: D DIF: Easy REF: 9.3
OBJ: 9.3.d. Identify the overall net reaction of glycolysis. MSC: Understanding
37. What does glycolysis accomplish for the cell?
a. It generates ADP for the cell to be used in other cycles.
b. It generates ATP and pyruvate for the cell to be used in other cycles.
c. It generates glucose to be used for storage.
d. It generates CO2 th
ANS: B DIF: Medium REF: 9.3
OBJ: 9.3.d. Identify the overall net reaction of glycolysis. MSC: Applying
38. In which of the following metabolic conversions is ATP "consumed" during glycolysis?
a. 1,3-Bisphosphoglycerate ? 3-phosphoglycerate
b. glucose ? glucose-6-phosphate
c. 2-Phosphoglycerate ? 3-phosphoglycerate
d. glucose-6-phosphate ? fructose-6-phosph
ANS: B DIF: Medium REF: 9.3
OBJ: 9.3.e. Distinguish between the energy investment of stage 1 and stage 2 of glycolysis.
MSC: Remembering
39. Which of the following best defines substrate-level phosphorylation?
a. direct transfer of a Pi to an ADP
b. direct transfer of a Pi to an ATP
c. indirect transfer of a Pi to an ATP
d. indirect transfer of a Pi to glucose
ANS: A DIF: Medium REF: 9.3
OBJ: 9.3.f. Define substrate-level phosphorylation. MSC: Remembering
40. Which of the following compounds contains a "high-energy" bond and is used to produce ATP
by substrate-level phosphorylation in glycolysis?
a. glucose
b. fructose-1,6-BP
c. 3-phosphoglycerate
d. 1,3-bisphosphoglycerate
ANS: D DIF: Medium REF: 9.3
OBJ: 9.3.f. Define substrate-level phosphorylation. MSC: Applying
41. The first reaction in glycolysis that produces a high-energy compound is catalyzed by
a. aldolase.
b. triose phosphate isomerase.
c. enolase.
d. phosphofructokinase-1.
ANS: D DIF: Easy REF: 9.3
OBJ: 9.3.h. Explain how phosphofructokinase-1 couples ATP hydrolysis with a phosphoryl
transfer reaction. MSC: Remembering
42. Fructose-1,6-bisphosphate is cleaved by aldolase. What is required for the reaction to proceed?
a. production of endergonic intermediate
b. substrate phosphorylation
c. cleaving of high-energy phosphate bond
d. formation of Schiff base intermediate
ANS: D DIF: Medium REF: 9.3
OBJ: 9.3.i. Identify how fructose-1,6-biphosphatase is cleaved by aldolase.
MSC: Understanding
43. Which coenzyme is required to convert glyceraldehyde-3-P into
1,3-bisphosphosphoglycerate?
a. FAD+
b. NAD+
c. ATP
d. Pi
ANS: B DIF: Easy REF: 9.3
OBJ: 9.3.j. Explain how glyceraldehyde-3-P is converted into 1,3-bisphosphoglycerate by
glyceraldehyde-3-P dehydrogenase. MSC: Understanding
44. How does phosphoglycerate kinase make glycolysis energy neutral at this step?
a. It uses ATP to produce 3-phosphoglycerate.
b. It produces 2 ATP along with 3-phosphoglycerate.
c. It results in a reaction at equilibrium.
d. It results in a reaction is
ANS: B DIF: Medium REF: 9.3
OBJ: 9.3.k. Describe how phosphoglycerate kinase replaces 2 ATP previously invested in
glycolysis. MSC: Applying
45. What advantage is there to phosphoglycerate kinase having an open and closed configuration?
a. It allows water to be trapped in the active site along with the substrate.
b. It forces covalent binding of the substrate to the enzyme active site.
c. The
ANS: C DIF: Medium REF: 9.3
OBJ: 9.3.k. Describe how phosphoglycerate kinase replaces 2 ATP previously invested in
glycolysis. MSC: Applying
46. Predict how oxygen saturation would be affected if an individual has defective hexokinase
enzymes.
a. 2,3-BPG levels are elevated and oxygen binding decreases.
b. 2,3-BPG levels are reduced and oxygen binding increases.
c. 2,3-BPG levels are elevated
ANS: B DIF: Difficult REF: 9.3
OBJ: 9.3.l. Explain why individuals with defects in glycolytic enzymes have altered
oxygen-transport capabilities. MSC: Applying
47. The enzyme phosphoglycerate mutase operates at ?G � 0 kJ/mol. That indicates that the
reversibility of that reaction
a. is spontaneous.
b. occurs rapidly.
c. occurs at equilibrium.
d. is nonspontaneous.
ANS: C DIF: Easy REF: 9.3
OBJ: 9.3.m. Demonstrate how phosphoglycerate mutase is a reversible reaction.
MSC: Applying
49. To produce 4 ATP requires 122 kJ/mol. Which reactions in the glycolytic pathway produce
enough energy to be able to overcome this deficit?
a. hexokinase, phosphofructokinase-1, and pyruvate kinase
b. hexokinase, phosphofructokinase-1, and pyruvate kin
ANS: B DIF: Easy REF: 9.3
OBJ: 9.3.n. Demonstrate using Gibbs free energy that glycolysis is an overall favorable
reaction pathway. MSC: Applying
50. Which of the following metabolic conversions is considered to be the major control point of
glycolysis?
a. fructose-1,6-bisphosphate ? dihydroxyacetone phosphate +
glyceraldehyde-3-phosphate
b. 1,3-Bisphosphoglycerate + ADP ? 3-Phosphoglycerate + ATP
ANS: D DIF: Medium REF: 9.3
OBJ: 9.3.g. List the three irreversible enzymatic reactions in glycolysis.
MSC: Applying
51. In glycolysis, fructose 1,6-bisphosphate is converted to two products with a standard
free-energy change (?G?�) of 23.8 kJ/mol. Under what conditions (encountered in
erythrocytes) will the free-energy change (?G) be negative, enabling the reaction to
ANS: D DIF: Difficult REF: 9.3
OBJ: 9.3.n. Demonstrate using Gibbs free energy that glycolysis is an overall favorable
reaction pathway. MSC: Analyzing
52. Where in the body is glucokinase found?
a. small intestine
b. liver
c. heart
d. thyroid
ANS: B DIF: Easy REF: 9.4
OBJ: 9.4.a. Explain the role of glucokinase in regulation of the glycolytic pathway.
MSC: Remembering
53. Hexokinase has a Km of 0.1 mM for glucose, whereas glucokinase has a Km of 10 mM for
glucose. What does that mean for their relative affinities for glucose?
a. Glucokinase has a higher affinity.
b. Hexokinase has a higher affinity.
c. Km does not meas
ANS: B DIF: Easy REF: 9.4
OBJ: 9.4.a. Explain the role of glucokinase in regulation of the glycolytic pathway.
MSC: Understanding
54. If blood glucose levels are elevated, what does glucokinase do in response?
a. inhibits glycolysis
b. stimulates the production of more hexokinase
c. stimulates the release of insulin
d. inhibits production of 2,3-BPG
ANS: C DIF: Medium REF: 9.4
OBJ: 9.4.a. Explain the role of glucokinase in regulation of the glycolytic pathway.
MSC: Understanding
55. If you are unable to digest milk products, what is the metabolic root of that issue?
a. maltase
b. lactase
c. sucrose
d. glucose oxidase
ANS: B DIF: Easy REF: 9.4
OBJ: 9.4.g. Describe metabolic roots of lactose intolerance. MSC: Understanding
56. In the presence of lactase, lactose is cleaved into the monosaccharides glucose and
a. glucose.
b. fructose.
c. galactose.
d. maltose.
ANS: C DIF: Easy REF: 9.4
OBJ: 9.4.g. Describe metabolic roots of lactose intolerance. MSC: Understanding
57. The rate limiting step can be defined as a level of enzyme activity that can be regulated to be
__________ even when substrate levels are __________.
a. high; high
b. low; high
c. high; low
d. low; low
ANS: B DIF: Easy REF: 9.4
OBJ: 9.4.c. Define rate limiting step. MSC: Remembering
58. What effect do elevated levels of ATP have on glycolysis?
a. decrease the affinity of PFK-1 for fructose-6-P and slow rate of the pathway
b. increase the affinity of PFK-1 for fructose-6-P and increase the rate of the pathway
c. increase the concentra
ANS: A DIF: Medium REF: 9.4
OBJ: 9.4.b. Explain how the conversion of phosphofructokinase-1 between the T and R state
is allosterically controlled by ATP, ADP, and AMP. MSC: Understanding
59. In the presence of high concentrations of ADP and F6P, how does the equilibrium shift
between the T state and R state of PFK-1? High concentrations of ADP and F6P
a. shift equilibrium to the R state.
b. shift equilibrium to the T state.
c. do not bind
ANS: A DIF: Medium REF: 9.4
OBJ: 9.4.b. Explain how the conversion of phosphofructokinase-1 between the T and R state
is allosterically controlled by ATP, ADP, and AMP. MSC: Applying
60. If a person has a deficiency in fructose-1-P, what effects does that have on the body?
a. Fructose-6-P concentrations increase.
b. Fructose-6-P is depleted.
c. ATP concentrations increase.
d. Glucose-6-P concentrations increase.
ANS: A DIF: Difficult REF: 9.4
OBJ: 9.4.b. Explain how the conversion of phosphofructokinase-1 between the T and R state
is allosterically controlled by ATP, ADP and AMP. MSC: Applying
61. List three ways in which flux is controlled through glycolysis.
a. regulation of aldolase, PFK-1, and supply and demand of intermediates
b. regulation of glucokinase, fructokinase, and number of intermediates
c. regulation of glucokinase, PFK-1, and c
ANS: D DIF: Difficult REF: 9.4
OBJ: 9.4.d. List three ways in which substrate availability and enzyme activity levels control
flux through the glycolytic pathway. MSC: Applying
62. Galactosemia is deficiency in which enzyme?
a. galactokinase
b. galactose-1-P uridyltransferase
c. UDP-galactose 4-epimerase
d. phosphoglucomutase
ANS: B DIF: Difficult REF: 9.4
OBJ: 9.4.i. Describe the effect of defective galactose-1-P uridylyltransferase.
MSC: Understanding
63. An infant who obtains nourishment from milk and who has galactosemia is unable to convert
a. galactose-1-P to glucose-6-P.
b. glucose-6-P to galactose-1-P.
c. galactose-1-P to glucose-1-P.
d. glucose-1-P to galactose-1-P.
ANS: C DIF: Difficult REF: 9.4
OBJ: 9.4.i. Describe the effect of defective galactose-1-P uridylyltransferase.
MSC: Applying
64. Glucokinase is a molecular sensor for which molecule?
a. glucose
b. lactose
c. galactose
d. maltose
ANS: A DIF: Easy REF: 9.4
OBJ: 9.4.e. Explain why glucokinase is a molecular sensor. MSC: Remembering
65. Which enzyme is the main regulator of glycolysis?
a. hexokinase
b. PFK-1
c. pyruvate kinase
d. aldolase
ANS: B DIF: Easy REF: 9.4
OBJ: 9.4.f. List the allosteric activators and inhibitors of phosphofructokinase-1.
MSC: Understanding
66. What is the potential metabolic fate of pyruvate under aerobic conditions?
a. produce lactate
b. produce ethanol
c. produce carbon dioxide and water
d. produce glucose
ANS: C DIF: Easy REF: 9.5
OBJ: 9.5.a. List the potential metabolic fates of pyruvate. MSC: Understanding
67. What is the potential metabolic fate of pyruvate during strenuous exercise?
a. produce lactate
b. produce ethanol
c. produce carbon dioxide and water
d. produce glucose
ANS: A DIF: Medium REF: 9.5
OBJ: 9.5.a. List the potential metabolic fates of pyruvate. MSC: Understanding
68. The NADH that is produced by glycolysis under anaerobic conditions is regenerated to NAD+
by the conversion of
a. acetaldehyde ? ethanol.
b. lactate ? pyruvate.
c. phosphoenolpyruvate ? pyruvate.
d. pyruvate ? lactate.
ANS: D DIF: Medium REF: 9.5
OBJ: 9.5.a. List the potential metabolic fates of pyruvate. MSC: Applying
69. What would the effect be of a lack of lactate dehydrogenase?
a. buildup of glucose
b. buildup of CO2
c. deficiency of ATP
d. deficiency of pyruvate
ANS: C DIF: Medium REF: 9.5
OBJ: 9.5.a. List the potential metabolic fates of pyruvate. MSC: Understanding
70. What is the fate of pyruvate in the presence of yeast, Saccharomyces cerevisiae?
a. converts to CO2 and ethanol
b. converts to H2O and CO2
c. converts to lactate and ethanol
d. converts to lactate and glucose
ANS: A DIF: Medium REF: 9.5
OBJ: 9.5.a. List the potential metabolic fates of pyruvate. MSC: Applying
71. Which of these cofactors participates directly in MOST of the redox reactions in the
fermentation of glucose to lactate?
a. ADP
b. ATP
c. NAD+/NADH
d. FAD/FADH2
ANS: C DIF: Medium REF: 9.5
OBJ: 9.5.a. List the potential metabolic fates of pyruvate. MSC: Remembering
72. When a mixture of glucose 6-phosphate and fructose 6-phosphate is incubated with the
enzyme phosphohexose isomerase, the final mixture contains twice as much glucose
6-phosphate as fructose 6-phosphate. Which one of the following statements is MOST
co
ANS: A DIF: Difficult REF: 9.3
OBJ: 9.3.n. Demonstrate using Gibbs free energy that glycolysis is an overall favorable
reaction pathway. MSC: Applying
73. Fructose 1,6-bisphosphate is converted to two products with a standard free energy of 23.8
kJ/mol. Under what condition(s) will this reaction become spontaneous?
a. spontaneous under any conditions
b. spontaneous under all conditions
c. when there is
ANS: D DIF: Medium REF: 9.3
OBJ: 9.3.n. Demonstrate using Gibbs free energy that glycolysis is an overall favorable
reaction pathway. MSC: Applying
74. During glycolysis, the steps between glucose and formation of glyceraldehyde-3-phosphate
a. consume 2 ATP and 2 NADH.
b. consume 2 ATP.
c. produce 2 ADP and 2 NADH.
d. produce 2 ATP and 2 NADH.
ANS: B DIF: Easy REF: 9.3
OBJ: 9.3.e. Distinguish between the energy investment of stage 1 and stage 2 of glycolysis.
MSC: Applying
75. Which reaction in glycolysis is a redox reaction?
a. glyceraldehyde-3-P ? 1,3-bisphosphoglycerate
b. glucose ? glucose-6-P
c. 2-phosphoglycerate ? phosphoenolpyruvate
d. fructose-6-P ? fructose-1,6-BP
ANS: A DIF: Easy REF: 9.3
OBJ: 9.3.a. Describe the glycolytic pathway. MSC: Understanding