ch04
Student: ___________________________________________________________________________
1.
Most enzymes are lipids.
True False
2.
Which of the following is NOT a characteristic of a catalyst?
A. is not changed itself at the end of the reaction
B. does not change the nature of the reaction
C. can change the final result of the reaction
D. increases the rate of the reaction
3.
In some instances RNA can act as an enzyme.
True False
4.
During a chemical reaction, a catalyst increases the rate at which the reaction occurs.
True False
5.
Catalysts increase reaction rates by lowering the activation energy of a reaction.
True False
6.
Ribozymes are RNA molecules that act as
A. hormones.
B. cofactors.
C. enzymes.
D. inhibitors.
7.
Enzymes ______________ the rate of a specific chemical reaction.
A. decrease
B. increase
C. have no effect on
8.
The rate at which a chemical reaction can be increased is by either ______________ the temperature or
______________ the activation energy.
A. increasing, increasing
B. increasing, decreasing
C. decreasing, decreasing
D. decreasing, increasing
9.
Cell extracts from which organism that could carry out fermentation caused vitalism to be questioned?
A.
B.
C.
D.
yeast
bacteria
amoebae
paramecia
10. Which of the following statements about enzymes is NOT true?
A. Enzymes increase chemical reaction rates.
B. Enzymes are consumed during a chemical reaction.
C. Enzymes decrease the free energy of activation of specific reactions.
D. Enzymes have unique pH and temperature optima.
11. The process that yeast uses to make alcohol from glucose is
A. fermentation.
B. aerobic respiration.
C. photosynthesis.
D. catalysis.
12. Biological catalysts
A. decrease reaction rates.
B. alter a reaction product.
C. remain unchanged at the end of the reaction.
D. All of these choices are correct.
13. Enzymes are specific for a given substrate.
True False
14. The substrate binds to the ______________ of the enzyme.
A. allosteric site
B. acidic site
C. neutral site
D. active site
15. The model that explains how an enzyme and substrate fit together is the
A. enzyme-substrate model.
B. lock-and-key model.
C. conformational model.
D. None of these choices are correct.
16. The model that describes how an enzyme can adjust its shape to fit the shape of the substrate is the
A. lock-and-key model.
B. enzyme-substrate model.
C. induced-fit model.
D. conformational model.
17. An enzyme elevated in the plasma of men with prostate cancer is
A. alkaline phosphatase.
B. catalase.
C. creatine kinase.
D. acid phosphatase.
18. The level of protein structure primarily involved in determining enzyme activity is the
A. primary structure.
B. secondary structure.
C. tertiary structure.
D. quaternary structure.
19. When an enzyme catalyzes a chemical reaction
A. the enzyme binds to the substrate's active site.
B. the enzyme's active site binds the product.
C. amino acids in the substrate allow for interaction with the product.
D. amino acids in the enzyme's active site interact with substrate molecules.
20. Elevated plasma aldolase could be indicative of
A. muscular dystrophy.
B. pancreatitis.
C. pernicious anemia.
D. prostate cancer.
21. Elevated plasma amylase could indicate
A. osteitis deformans.
B. a myocardial infarct.
C. obstructive jaundice.
D. a perforated peptic ulcer.
22. Reactant molecules of enzyme action are called
A. substrates.
B. allosteric inhibitors.
C. cofactors.
D. products.
23. Pyruvate dehydrogenase catalyzes the removal of hydrogen from pyruvic acid.
True False
24. The conversion of glucose to galactose is catalyzed by an isomerase.
True False
25. Isomers are different forms of an enzyme.
True False
26. Isoenzymes bind different substrates and catalyze different chemical reactions.
True False
27. Abnormally high concentration of the BB form of creatine phosphokinase is associated with a myocardial
infarction.
True False
28. The MM isoenzyme of creatine phosphokinase is found in skeletal muscle.
True False
29. Digestive enzymes which remove hydrogen atoms from their substrates are referred to as
A. dehydrogenases.
B. hydrolases.
C. catalases.
D. peroxidases.
30. The breakdown of hydrogen peroxide is catalyzed by
A. aldolase.
B. amylase.
C. catalase.
D. kinase.
31. Addition of phosphate groups to a particular molecule is catalyzed by
A. transaminases.
B. phosphatases.
C. isomerases.
D. kinases.
32. Hydrolysis reactions are catalyzed by
A. dehydrogenases.
B. hydrolases.
C. isomerases.
D. synthases.
33. Dehydration synthesis reactions are catalyzed by
A. dehydrogenases.
B. hydrolases.
C. isomerases.
D. synthases.
34. Which of the following does NOT affect the activity of an enzyme?
A. the organ the enzyme is in
B. concentration of enzyme and substrate molecules
C. concentration of cofactors and coenzymes
D. pH and temperature
35. In general, decreased body temperature causes the rate of enzymatic reactions to decrease.
True False
36. The pH optimum for enzymes secreted by the stomach is higher than the pH optimum for enzymes
secreted by the pancreas.
True False
37. The pH optima for all digestive enzymes are approximately equal to the pH of blood.
True False
38. An enzyme-catalyzed reaction in the body at 50°C will proceed at a faster rate than at 35°C.
True False
39. The phosphatase found in bone would have a pH optimum that is ______________ than the pH optimum
of the phosphatase found in the prostate gland.
A. higher
B. lower
C. the same as
40. The enzyme with the lowest pH optimum is
A. acid phosphatase.
B. lipase.
C. monoamine oxidase.
D. pepsin.
41. In an enzymatic reaction, when temperature is increased past the point of "optimal temperature," the
enzyme starts to
A. increase its catalytic activity.
B. reduce its catalytic activity.
C. increase its allosteric properties.
D. increase product formation.
42. Coenzymes are organic molecules that are required for proper enzyme function.
True False
43. A deficiency of dietary copper could limit the activity of some enzymes.
True False
44. Metal ions such as magnesium or calcium can serve as enzyme
A. coenzymes.
B. ribozymes.
C. substrates.
D. cofactors.
45. Which of the following is NOT true about enzymes?
A. As the temperature increases from 25°C to 37°C enzyme activity decreases.
B. Very few enzymes require cofactors.
C. Most enzymes are not sensitive to changes in pH.
D. All of these choices are not true.
46. Which of the following is NOT true of catalysts?
A. They are unchanged by the reaction catalyzed.
B. They allow endergonic reactions to become exergonic reactions.
C. They increase the amount of energy released by a chemical reaction.
D. All of these choices are not true.
47. Active enzymes are often called zymogens.
True False
48. ______________ are inactive forms of digestive enzymes.
A. Cofactors
B. Coenzymes
C. Zymogens
D. Both cofactors and zymogens are correct.
49. At saturation, enzyme activity is maximal.
True False
50. The principle that reversible reactions will be driven from the side of the equation where the
concentration is lower to the side where the concentration is higher is known as the law of mass
action.
True False
51. In the reaction (H2O + CO2 -> H2CO3), increasing the concentration of H2O would
A. decrease the concentration of H2CO3.
B. increase the concentration of H2CO3.
C. increase the concentration of CO2.
D. have no effect on either CO2 or H2CO3 concentrations.
52. Addition of substrate when enzyme reaction rate is maximal results in
A. additional product formation.
B. less product formation.
C. no change in product formation.
D. enzyme destruction.
53. Most enzymatic reactions in the body are one step processes.
True False
54. Enzymes in a metabolic pathway act antagonistically to produce a final product.
True False
55. End-product inhibition usually involves allosteric inhibition of an enzyme.
True False
56. Regulation of a metabolic pathway by the final product of the pathway is termed
A. allosteric inhibition.
B. end-product inhibition.
C. negative feedback.
D. Both end-product inhibition and negative feedback are correct.
57. ______________ occurs when the product of a metabolic pathway binds to an enzyme and decreases
enzymatic activity.
A. Allosteric inhibition
B. End-product inhibition
C. Second messaging
D. Coupling
58. A defect in the enzyme which converts phenylalanine into tyrosine is characteristic of the disease
A. phenylketonuria.
B. albinism.
C. lactose intolerance.
D. maple-syrup disease.
59. A defect in the enzyme that catalyzes the formation of melanin from DOPA results in
A. phenylketonuria.
B. albinism.
C. lactose intolerance.
D. maple-syrup disease.
60. In response to increased concentration of the final product of a metabolic pathway
A. all enzymes in the pathway become more active.
B. intermediate enzymes become more active.
C. the final product acts as an allosteric regulator of one enzyme in the pathway.
D. all enzymes in the pathway become less active.
61. Decreased phenylalanine metabolism causes
A. albinism.
B. hypercholeteremia.
C. lactose intolerance.
D. Tay-Sachs disease.
62. An inborn error in lipid metabolism may cause all of the following diseases EXCEPT
A. Tay-Sachs disease.
B. homocystinuria.
C. hypercholesteremia.
D. Gaucher's disease.
63. Free energy is the only type that can be used to perform cellular work.
True False
64. The amount of entropy increases as bonds are broken to generate glucose from glycogen.
True False
65. Energy transformations result in a(n) ______________ in entropy.
A. increase
B. decrease
C. no change
66. Cellular respiration results in a(n) ______________ in entropy as glucose is broken down to form carbon
dioxide.
A. increase
B. decrease
C. no change
67. The flow of energy in living systems is termed
A. entropy.
B. enthalpy.
C. bioenergetics.
D. bioluminescence.
68. Energy transformations increase the entropy of a system is a statement of the
A. first law of thermodynamics.
B. second law of thermodynamics.
C. law of mass action.
D. law of conservation of energy.
69. Energy can change forms, but cannot be created or destroyed is a statement of the
A. first law of thermodynamics.
B. second law of thermodynamics.
C. law of mass action.
D. third law of thermodynamics.
70. Another name for the first law of thermodynamics is the law of conservation of energy.
True False
71. The greatest increase in entropy occurs
A. when starch is degraded to glucose.
B. when amylase produces maltose.
C. when glucose is converted to galactose.
D. when ATP is synthesized.
72. Exergonic reactions proceed with the release of energy.
True False
73. Free energy is ______________ when exergonic reactions proceed.
A. increased
B. decreased
C. unchanged
74. Endergonic reactions cause the amount of entropy in the products to be
A. increased.
B. decreased.
C. unchanged.
75. A ______________ is the amount of heat required to raise the temperature of one cubic centimeter of
water one degree on the Celsius scale.
A. specific heat
B. meter
C. boiling point
D. calorie
76. A food calorie (Calorie) is equivalent to which metric measurement of heat?
A. calorie
B. joule
C. kilocalorie
D. watt
77. The reaction of adenosine diphosphate and phosphate generates adenosine triphosphate and energy.
True False
78. ______________ is the universal energy carrier.
A. Glucose
B. ATP
C. ADP
D. GTP
79. In bioenergetic pathways, as intermediates are acted upon by enzymes, the ultimate result is the release
of
A. lactate.
B. ATP.
C. free energy.
D. enzymes.
80. Oxidizing agents accept electrons from molecules undergoing reduction.
True False
81. A reducing agent donates electrons to a molecule.
True False
82. Oxidation means that oxygen is part of the reaction.
True False
83. An atom or molecule that is oxidized is also a reducing agent.
True False
84. A molecule that gains a hydrogen is also oxidized.
True False
85. Reduction and oxidation are always coupled.
True False
86. NAD is derived from the vitamin
A. B-12.
B. B-3, niacin.
C. B-2, riboflavin.
D. B-6.
87. FAD is derived from vitamin
A. B-12.
B. B-3, niacin.
C. B-2, riboflavin.
D. B-6.
88. Chemically reduced FAD has __________ extra hydrogen atom(s) bound to it.
A. one
B. two
C. three
D. no
89. Oxidized nicotinamide adenine dinucleotide (NAD) has ______________ two electrons.
A. lost
B. gained
C. shared
90. If NAD becomes reduced it is a(n)
A. reducing agent.
B. oxidizing agent.
C. zymogen.
D. allosteric inhibitor.
91. During oxidation, a molecule or atom
A. gains protons.
B. loses protons.
C. gains electrons.
D. loses electrons.
92. During reduction, a molecule or atom
A. gains protons.
B. loses protons.
C. gains electrons.
D. loses electrons.
93. A reducing agent
A. donates protons to an atom or molecule.
B. donates electrons to an atom or molecule.
C. accepts protons from an atom or molecule.
D. accepts electrons from an atom or molecule.
94. A common oxidizing agent used to couple chemical reactions in cells is
A. riboflavin.
B. niacin.
C. NADH.
D. FAD.
95. A common reducing agent used to couple chemical reactions in cells is
A. riboflavin.
B. niacin.
C. NADH.
D. FAD.
96. FAD and NAD are coenzymes that act as _______ in biochemical reactions.
A. hydrogen carriers
B. oxygen carriers
C. energy carriers
D. vitamin carriers
97. Consuming extra niacin and riboflavin in the diet will provide extra energy for body functions.
True False
ch04 Key
1. FALSE
2. C
3. TRUE
4. TRUE
5. TRUE
6. C
7. B
8. B
9. A
10. B
11. A
12. C
13. TRUE
14. D
15. B
16. C
17. D
18. C
19. D
20. A
21. D
22. A
23. TRUE
24. TRUE
25. FALSE
26. FALSE
27. FALSE
28. TRUE
29. A
30. C
31. D
32. B
33. D
34. A
35. TRUE
36. FALSE
37. FALSE
38. FALSE
39. A
40. D
41. B
42. TRUE
43. TRUE
44. D
45. D
46. B
47. FALSE
48. C
49. TRUE
50. FALSE
51. B
52. C
53. FALSE
54. FALSE
55. TRUE
56. D
57. A
58. A
59. B
60. C
61. A
62. B
63. TRUE
64. TRUE
65. A
66. A
67. C
68. B
69. A
70. TRUE
71. A
72. TRUE
73. B
74. B
75. D
76. C
77. FALSE
78. B
79. C
80. TRUE
81. FALSE
82. FALSE
83. TRUE
84. FALSE
85. TRUE
86. B
87. C
88. B
89. A
90. B
91. D
92. C
93. B
94. D
95. C
96. A
97. FALSE
ch04 Summary
Category
Blooms: Applying
Blooms: Remembering
Blooms: Understanding
Fox - Chapter 04
# of Question
s
4
74
19
97