Test Bank Docx Ch11 Carbohydrates Structure and Function

Test questions for Chapter 11

Carbohydrates: Structure and Function

1. The most common disease in the world is
   1. heart disease.
   2. cancer.
   3. tooth decay.
   4. amoebic dysentery.
   5. malaria.
2. Which of the following classes of biomolecules causes dental caries?
   1. carbohydrates
   2. proteins
   3. fats
   4. nucleic acids
   5. All foods cause dental caries.
3. Which of the following statements related to the formation of dental caries is FALSE?
   1. Anaerobic bacteria produce lactic acid.
   2. Anaerobic bacteria convert glucose into carbon dioxide and water.
   3. Lactic acid reduces the pH of the environment of the tooth enamel to pH 4–5.
   4. Tooth enamel dissolves in a pH 4–5 environment.
   5. Brushing removes sugars from the teeth.
4. Which of the following best describes how brushing your teeth prevents cavities?
   1. Toothpaste stops the metabolism of glucose.
   2. Toothpaste neutralizes lactic acid.
   3. Brushing removes sugars.
   4. Brushing removes anaerobic bacteria.
   5. Toothpaste increases pH in the mouth.
5. Which of the following foods contain carbohydrates?
   1. pineapple
   2. tomatoes
   3. potatoes
   4. wheat
   5. All of these foods contain carbohydrates.
6. Which of the following statements best describes photosynthesis?
   1. the breakdown of starch into CO₂, H₂O, and energy
   2. the breakdown of starch into CO₂ and H₂O using energy
   3. the synthesis of starch from CO₂, H₂O, and energy
   4. the synthesis of starch and energy from CO₂ and H₂O
   5. Photosynthesis applies to all of the above processes.
7. In what part of the body does the metabolism of carbohydrates begin?
   1. in the mouth
   2. in the stomach
   3. in the pancreas
   4. in the small intestine
   5. in the large intestine
8. What is produced by cellular respiration?
   1. oxygen
   2. sugars
   3. carbon dioxide, water, and energy
   4. oxygen and energy
   5. oxygen, sugars, and energy
9. Which of the following is NOT a function of carbohydrates?
   1. Carbohydrates are used for long term energy storage.
   2. Carbohydrates are fuels for cells.
   3. Carbohydrates are part of DNA and RNA.
   4. Carbohydrates are used in cellular recognition.
   5. Carbohydrates make some foods taste sweet.
10. Which of the following features is NOT shared by all monosaccharides?
    1. Monosaccharides cannot be hydrolyzed into simpler carbohydrates.
    2. Monosaccharides all contain six carbons.
    3. Monosaccharides have an aldehyde or a ketone.
    4. Monosaccharides contain two or more alcohols.
    5. Actually, all of these statements are true.
11. Which of the following types of carbohydrates can be hydrolyzed to give smaller molecules?
    • 1. monosaccharides
      2. disaccharides
      3. oligosaccharides
      4. polysaccharides
12. I only
13. II and IV only
14. III only
15. I and II only
16. II, III, and IV
17. Which of the following is a monosaccharide?
    1. cellulose
    2. starch
    3. glucose
    4. sucrose
    5. maltose
18. Which of the following structures is a monosaccharide?

a. b. c. d. e.

1. Do you expect monosaccharides to be soluble in water?
   1. Yes, because monosaccharides are acidic
   2. No, because monosaccharides have too many carbons to be soluble
   3. Yes, because monosaccharides can hydrogen bond with water
   4. No, because monosaccharides cannot form intermolecular attractive forces with water
   5. Yes, because monosaccharides are basic
2. Which carbon(s) in the Fischer projection below is/are a center of chirality?

1. Which carbon(s) in the Fischer projection below is/are tetrahedral?

1. The Fischer projection for fructose is shown below. How many carbons does fructose contain?

1. The Fischer projection for fructose is shown below. Which functional group(s) does fructose contain?

1. The Fischer projection for fructose is shown below. Which carbon determines whether the sugar is d- or l-?

1. The Fischer projection for fructose is shown below. Is it a d-sugar or an l-sugar?

1. Which carbon determines whether the sugar below is d- or l-?

1. Which of the following sugars is the enantiomer of d-glucose?

a. b. c. d. e.

1. d-glucose is shown below. Which of the choices below it is l-glucose?

a. b. c. d. e.

1. What is the relationship between d- and l-glucose?
   1. They are identical.
   2. They are constitutional isomers.
   3. They are diastereomers.
   4. They are enantiomers.
   5. They are conformers.
2. Nature produces predominantly _______-carbohydrates and _______-amino acids.
3. d, d
4. d, l
5. l, d
6. l, l
7. Nature does not favor one stereoisomer over another.
8. Which one of these molecules is a naturally occurring sugar?

1. Only one of the following molecules is a naturally occurring sugar. Which of the following statements is a reason that only one of the sugars is naturally occurring?

1. Naturally occurring sugars do not have multiple hydroxyl groups on a single carbon.
2. D-sugars are much more common than l-sugars.
3. Naturally occurring sugars are polyhydroxylated.
4. Naturally occurring sugars contain a carbonyl.
5. All of the above are true statements.
6. The structures of mannose and galactose are given below. What is the relationship between these two monosaccharides?

1. They are identical.
2. They are constitutional isomers.
3. They are diastereomers.
4. They are enantiomers.
5. They are conformers.
6. Which of the following statements does NOT describe the anomeric carbon?
7. It is the carbon of the carbonyl in the open-chain form of the sugar.
8. This carbon is attached to two oxygens.
9. The hydroxyl group on this carbon can be above or below the ring.
10. Glucose does not contain an anomeric carbon.
11. The anomeric carbon is a center of chirality.
12. In which of the sugars below is the arrow pointing to the carbon that determines whether a sugar is α- or β-?

a. b. c. d. e.

1. In which of the following Haworth projections is the arrow pointing to the anomeric carbon?

a. b. c. d. e.

1. In which of the following Haworth projections is the arrow pointing to the anomeric carbon?

1. How can it be determined whether a sugar is α- or β- by looking at the Haworth projection?
2. α-anomer: The –OH on the anomeric carbon is above the ring.

β-anomer: The –OH on the anomeric carbon is below the ring.

1. α-anomer: The –CH₂OH of carbon 6 is above the ring.

β-anomer: The –CH₂OH of carbon 6 is below the ring.

1. α-anomer: The –OH on the anomeric carbon is below the ring.

β-anomer: The –OH on the anomeric carbon is above the ring.

1. α-anomer: The –CH₂OH of carbon 6 is below the ring.

β-anomer: The –CH₂OH of carbon 6 is above the ring.

1. Both b and d are true.
2. Which of the following structures is an α-anomer?

a. b. c. d. e.

1. The circled carbon in the cyclic structure of glucose corresponds to which boxed carbon in the linear structure?

glucose

1. The circled oxygen in the cyclic structure of glucose corresponds to which boxed oxygen in the linear structure?

glucose

1. The open chain form of a carbohydrate contains a carbonyl group. This carbonyl group reacts to become an alcohol when the ring closes, forming the anomeric carbon. The type of carbonyl determines which type of ring is formed. Select the choice in which the type of carbonyl is paired with the correct type of ring that is formed.
2. ketone and pyranose
3. aldehyde and pyranose
4. carboxylic acid and furanose
5. carboxylic acid and pyranose
6. aldehyde and furanose
7. Below is the open-chain form of fructose, followed by several cyclic monosaccharides. Choose the cyclic monosaccharides that are the ring form of fructose.

1. Only structure II is d-fructose.
2. Only structure III is d-fructose.
3. Both structures I and II are d-fructose.
4. Both structure III and IV are d-fructose.
5. All of these structures are d-fructose.
6. The ring form with the ring structure shown at left below is called a ________, and the ring form with the ring structure to the right below is called a _________.

1. pyranose; pyranose
2. pyranose; furanose
3. furanose; furanose
4. furanose; pyranose
5. The choices given do not apply to ring forms of sugars.
6. Which of the following statements best describes mutarotation?
7. The open chain, α-anomer and β-anomer of a sugar are in equilibrium in solution.
8. The sugar spins around (rotates) in solution.
9. The sugar mutates in solution.
10. The sugar decomposes in solution.
11. The sugar both spins around and mutates in solution.
12. Which of the following statements best explains how mutarotation occurs in solution?
13. Any C-C can break, opening the ring.
14. The hydroxyl group on the anomeric carbon “floats” between the α and the β position.
15. The hydroxyl group on the anomeric carbon comes off and then reattaches.
16. The bond between the ring oxygen and the anomeric carbon breaks, opening the ring, and then reforms, closing the ring again.
17. All of the above can occur in solution.
18. Which of the following species does equilibrium favor in solution?

I II III

1. I
2. II
3. III
4. II and III
5. There are equal concentrations of these three species in solution.
6. The figure below illustrates a(n)

1. monosaccharide.
2. simple sugar.
3. disaccharide.
4. polysaccharide.
5. oligosaccharide.
6. How are disaccharides separated into two monosaccharides?
   1. It is not possible to separate disaccharides into monosaccharides.
   2. by esterification
   3. by hydration
   4. by hydrolysis
   5. by amidation
7. Which of the following arrows is pointing to a glycosidic bond?

• 1. a only
  2. b only
  3. c only
  4. b and c
  5. b, c, and d

1. Which of the following arrows is pointing to a glycosidic bond?

1. a only
2. b only
3. c only
4. b and c
5. b, c, and d
6. How are glycosidic linkages broken during catabolism of sugars?
7. by oxidation
8. by reduction
9. by hydrolysis
10. by hydrogenation
11. by dehydration
12. Which of the following glycosidic linkages does the sugar shown below contain?

1. β-(2→4)
2. α-(1→4)
3. β-(1→4)
4. α-(2→4)
5. α-(2→6)
6. Which of the following glycosidic linkages does the sugar shown below contain?

1. β-(2→4)
2. α-(1→4)
3. β-(1→4)
4. α-(2→4)
5. α-(2→6)
6. This disaccharide has glycosidic bonds to the anomeric carbons of both monosaccharides.

a. lactose

b. sucrose

c. cellobiose

d. maltose

e. both cellobiose and maltose

1. This disaccharide is composed of two glucose molecules.

a. lactose

b. sucrose

c. cellobiose

d. maltose

e. both cellobiose and maltose

1. This disaccharide is the common type of sugar that comes from sugar cane or beets.

a. lactose

b. sucrose

c. cellobiose

d. maltose

e. both cellobiose and maltose

1. This disaccharide is found in milk.

a. lactose

b. sucrose

c. cellobiose

d. maltose

e. both cellobiose and maltose

1. A disaccharide has an α-(1→4) glycosidic linkage. Which statement about this sugar is true?
2. Both monosaccharides in the disaccharide are linked at their anomeric carbon.
3. Both monosaccharides in the disaccharide are the α anomer.
4. No part of the disaccharide can undergo mutarotation.
5. The closed ring form of the sugar linked at its carbon-4 is in equilibrium with its open-chain form.
6. All of these statements are true.
7. Cellobiose, shown below, cannot be hydrolyzed into monosaccharides by humans. Which statement best describes why this is the case?

Cellobiose

• 1. Cellobiose contains a β-(1→4) glycosidic linkage, which is not a substrate for glycosidases in the human stomach.
  2. Human enzymes do not accept glucose molecules as substrates.
  3. Cellobiose is composed of monosaccharides that are not part of the human diet.
  4. The glycosidic bond in this disaccharide is unusually strong.
  5. No disaccharide is hydrolyzed by humans.

1. What is the product(s) of the hydrolysis of the following sugar?

Sucrose

1. What type of saccharide is the following molecule?

1. a monosaccharide
2. a disaccharide
3. an oligosaccharide
4. a polysaccharide
5. This molecule is not a sugar.
6. How many monosaccharides are produced when the following sugar is hydrolyzed?

1. 0
2. 1
3. 2
4. 3
5. 4
6. Starches in our diet contain _________ of glucose units bonded together.
7. tens
8. hundreds
9. thousands
10. millions
11. billions
12. A large molecule composed of many repeating units of smaller molecules is called a
13. polymer.
14. monomer.
15. manymer.
16. macromere.
17. carbohydrate.
18. Which of the following molecules is NOT a polysaccharide?
    1. amylose
    2. amylopectin
    3. cellulose
    4. glycogen
    5. glucose
19. The most common polysaccharides found in plants and animals are polymers of
20. galactose.
21. glucose.
22. fructose.
23. glucose and fructose.
24. glucose, fructose, and galactose.
25. Animals store energy in the form of
    1. amylose.
    2. amylopectin.
    3. glycogen.
    4. cellulose.
    5. amylose and amylopectin.
26. Plants store energy in the form of
    1. amylose.
    2. amylopectin.
    3. glycogen.
    4. cellulose.
    5. amylose and amylopectin.
27. These polysaccharides are made of glucose.
    1. amylose
    2. amylopectin
    3. glycogen
    4. cellulose
    5. all of the above
28. Animals cannot digest________, but ruminants such as horses and cows have bacteria in their digestive track that can digest it.
    1. amylose
    2. amylopectin
    3. glycogen
    4. cellulose
    5. amylose and amylopectin
29. Cellulose and starch are similar in that they are both polymers of glucose. Cellulose, however, forms sheet-like structures, which give rigidity to a plant, whereas starch forms spirals. What accounts for this difference in macroscopic structure?
30. Cellulose is composed of d-glucose, whereas starch is composed of l-glucose.
31. Cellulose and starch are connected together on different carbons.
32. Cellulose is composed of l-glucose, whereas starch is composed of d-glucose.
33. Cellulose has a β-(1→4) linkage, whereas starch has an α-(1→4) linkage.
34. Starch has a β-(1→4) linkage, whereas cellulose has an α-(1→4) linkage.
35. Most animals cannot digest cellulose. However, those with a second stomach, containing specific bacteria that produce β-glycosidases, can digest cellulose. What is the role of the β-glycosidase in digesting cellulose?
36. β-glycosidase catalyzes the oxidation of cellulose.
37. β-glycosidase catalyzes the isomerization of β-glycosidic bonds into α-glycosidic bonds.
38. β-glycosidase catalyzes the reduction of cellulose.
39. β-glycosidase catalyzes the hydrolysis of cellulose.
40. β-glycosidase catalyzes the dehydration of cellulose.
41. Which statement best describes how a cell distinguishes between a host cell and foreign cell?
42. Antibodies detect foreign cells.
43. This is what T-cells do.
44. Oligosaccharide cell markers on the surface of the cell do this.
45. A cell sends out special proteins to do this.
46. The proteins within the cell membrane do this.
47. Type _____ blood is the universal donor, whereas type _____ is the universal recipient.
48. O; AB
49. AB; O
50. A; B
51. B; A
52. O; A or B
53. Which statement best describes at the molecular level why AB is the universal acceptor?
54. It is the least common blood type.
55. It contains both the type A and type B monosaccharides in addition to the core trisaccharide.
56. It only contains the core trisaccharide and does not have any additional sugars on it.
57. Red blood cells of this type do not have any oligosaccharide markers.
58. Type AB has a completely different oligosaccharide marker than A, B, and O.
59. Which of the following blood types is most common?
60. A
61. B
62. AB
63. O
64. They are equally common.
65. Which of the following blood types can be donated to someone with type A blood?
66. type A only
67. type A or type O
68. type A or type AB
69. any of the blood types except A
70. Type A can receive blood from any of the blood types.
71. A patient undergoing a kidney transplant is given a kidney from a person with type B blood when the patient is, in fact, type O. What effect of this mistake would be most likely?
72. Nothing, blood type does not matter in organ transplants.
73. Nothing, Type O is the universal recipient.
74. organ failure
75. coma
76. a mild allergic reaction

1. Which of the following sugars is called “blood sugar”?
2. glucose
3. glycogen
4. fructose
5. sucrose
6. All of the above
7. Insulin acts to __________, whereas glucagon __________.
8. increase blood sugar; decreases blood sugar
9. stimulate gluconeogenesis; stimulates glycogenesis
10. suppress gluconeogenesis; suppresses glycogenesis
11. decrease blood sugar; increases blood sugar
12. stimulate glycogenesis; suppresses glycogenesis
13. The result of a patient’s Fasting Plasma Glucose Test is 60 mg glucose per deciliter. This patient is
14. normal.
15. hypoglycemic.
16. hyperglycemic.
17. diabetic.
18. both hyperglycemic and diabetic.
19. A patient with chronic pancreatitis has her pancreas removed. Which of the following effects would be most likely?
20. nothing
21. the regeneration of the pancreas
22. Type I diabetes
23. Type II diabetes
24. hypoglycemia
25. Which of the following is the best definition for diabetes?
26. Diabetes is hypoglycemia due to an excess of insulin.
27. Diabetes is hypoglycemia due to insulin resistance or insufficient insulin.
28. Diabetes is hyperglycemia due to an excess of insulin.
29. Diabetes is hyperglycemia due to insulin resistance or insufficient insulin.
30. Diabetes is any disorder of blood sugar.
31. Which of the following statements describes the role of insulin in the body?
    • 1. Insulin signals to cells to allow glucose to enter.
      2. Insulin stimulates the conversion of glucose to glycogen.
      3. Insulin stimulates the hydrolysis of glucose from glycogen.
32. All of these describe the role of insulin in the body.
33. I only
34. II only
35. III only
36. I and II
37. Which of the following choices matches the descriptions of Type I and Type II diabetes and their treatments?

1. Why can’t insulin be taken orally?
2. It does not taste very good.
3. Enzymes in the saliva break it down.
4. Hydrolysis of insulin occurs in the stomach.
5. It is not possible to store insulin.
6. All of the above