Full Test Bank Chapter.22 Carbohydrates 13th Edition

Package Title: Solomons Test Bank

Course Title: Solomons 12e

Chapter Number: 22

Question type: Multiple Choice

1) What compounds are formed upon oxidation of glucose?

a) CO₂, H₂O, CH₃OH

b) CH₂OH(CHOH)₄COOH

c) CO, H₂O

d) CO₂, H₂O

e) C₆H₁₂O₆

Topic: General

Section: 22.1

Difficulty Level: Easy

) What are carbohydrates?

a) I, II, III

b) I, II

c) II, III

d) I, II, III, IV

e) III, IV

Topic: General

Section: 22.1

Difficulty Level: Easy

3) Which is a ketohexose?

a) d-Glucose

b) d-Fructose

c) d-Mannose

d) d-Ribose

e) (+)-Sucrose

Topic: Nomenclature, Definitions and Types of Carbohydrates

Section: 22.2

Difficulty Level: Easy

4) Which are the anomers?

a) I and II

b) I and III

c) II and III

d) II and IV

e) III and IV

Topic: Nomenclature, Definitions and Types of Carbohydrates

Section: 22.2

Difficulty Level: Easy

5) When the name of a monosaccharide is preceded only by (+), it can be said, correctly, that:

a) The compound is the α-anomer.

b) The compound exists in the pyranose form.

c) The compound is dextrorotatory.

d) The compound has the same stereochemistry at the penultimate carbon as d-(+)-glucose.

e) The compound exists only in open-chain form.

Topic: Nomenclature, Definitions and Types of Carbohydrates

Section: 22.2

Difficulty Level: Easy

6) Refer to the structures below. Which are l-sugars?

a) II and IV

b) I, II, and III

c) I and V

d) III, IV, and V

e) IV and V

Topic: Combination problems

Section: 22.2

Difficulty Level: Easy

7) Which of the following structures represent enantiomers?

a) I and II

b) II and III

c) III and IV

d) III and V

e) IV and V

Topic: Stereochemical Considerations

Section: 22.2

Difficulty Level: Medium

8) How many stereoisomers of the l series would exist for the following pentose?

O=CHCHOHCHOHCHOHCH₂OH

a) 2

b) 3

c) 4

d) 5

e) 8

Topic: Nomenclature, Definitions and Types of Carbohydrates

Section: 22.2

Difficulty Level: Medium

9) Which of the following is an l-aldotetrose?

a) I

b) II

c) III

d) IV

e) V

Topic: Nomenclature, Definitions and Types of Carbohydrates

Section: 22.2

Difficulty Level: Medium

10) Which of the following is a d-aldotetrose?

a) I

b) II

c) III

d) IV

e) V

Topic: Nomenclature, Definitions and Types of Carbohydrates

Section: 22.2

Difficulty Level: Medium

11) Which of these is α-d-glucopyranose?

a) I

b) II

c) III

d) IV

e) V

Topic: Nomenclature, Definitions and Types of Carbohydrates

Section: 22.2

Difficulty Level: Medium

12) What are the correct designations for the stereogenic centers in this aldose:

a) 2R,3S,4R

b) 2R,3S,4S

c) 2S,3R,4R

d) 2S,3S,4R

e) 2R,3R,4S

Topic: Stereochemical Considerations

Section: 22.2

Difficulty Level: Hard

13) Sugars that undergo mutarotation in neutral aqueous solution are:

a) I and III

b) III and IV

c) II, III, and IV

d) I, II, and V

e) I and IV

Topic: Nomenclature, Definitions and Types of Carbohydrates

Section: 22.3

Difficulty Level: Medium

14) Which would undergo mutarotation in neutral aqueous solution?

a) I

b) II

c) III

d) IV

e) I, II and III

Topic: Stereochemical Considerations

Section: 22.3

Difficulty Level: Medium

15) Consider the structures shown below. Which structure represents -d-glucopyranose?

a) I

b) II

c) III

d) IV

e) V

Topic: Nomenclature, Definitions and Types of Carbohydrates

Section: 22.3

Difficulty Level: Medium

16) Which of these is a glycoside?

a) I

b) II

c) III

d) IV

e) V

Topic: Nomenclature, Definitions and Types of Carbohydrates

Section: 22.4

Difficulty Level: Easy

17) A glycoside is a compound which contains the structural features of these classes of organic compounds:

a) Aldehydes and alcohols

b) Acetals and alcohols

c) Hemiacetals and alcohols

d) Ketones and alcohols

e) Alcohols and carboxylic acids

Topic: Nomenclature, Definitions and Types of Carbohydrates

Section: 22.4

Difficulty Level: Easy

18) Which reagent would be used for the following transformation?

a) CH₃I, KOH

b)

c) CH₃OH, HCl

d) (CH₃)₂SO₄, NaOH

e)

Topic: Reagents

Section: 22.4

Difficulty Level: Easy

19) What compounds (other than methanol) would be formed in the solution if the glycoside presented below was treated with dilute aqueous hydrochloric acid and the solution allowed to stand?

a) I and II

b) I and III

c) II and III

d) I, III, and IV

e) II, III, and IV

Topic: Reactions

Section: 22.4

Difficulty Level: Medium

20) Which reagent would cause the following conversion to take place?

a) Excess CH₃OH and KOH

b) Excess CH₃OH and HCl

c) Excess (CH₃)₂SO₄ and OH^–

d) Excess CH₃I and H₃O⁺

e) Excess (CH₃CO)₂O

Topic: Reagents

Section: 22.5

Difficulty Level: Easy

21) How the tautomerization of a carbohydrate could be prevented?

a) Perform a Fischer methylation of the anomeric OH group.

b) Perform permethylation of the carbohydrate.

c) Treat the carbohydrate with LiAlH₄.

d) Prepare a solution of the carbohydrate in Br₂/H₂O

e) It is impossible to prevent tautomerization.

Topic: Tautomerization

Section: 22.5

Difficulty Level: Medium

22) Which of these is a component of the mixture formed when d-galactose is placed in aqueous base (de Bruyn–van Ekenstein transformation)?

a) I

b) II

c) III

d) IV

e) V

Topic: Product Ratios

Section: 22.5

Difficulty Level: Medium

23) What reagents could be used to selectively protect the HO groups at positions 1 and 6 of a hexose?

a) TBDPS-Cl, AgNO₃ followed by acetic anhydride.

b) CH₃OH/HCl followed by TBDPS-Cl.

c) CH₃CO₂H, HCl followed by (CH₃)₃C(C₆H₅)₂-SiCl.

d) Acetic anhydride followed by acetone.

e) Benzaldehyde followed by CH₃OH/HCl.

Topic: Protecting Groups

Section: 22.5

Difficulty Level: Hard

24) Which of these pyranose forms of an aldohexose can react with two equivalents of acetone in the presence of acid ?

a) I

b) II

c) III

d) IV

e) V

Topic: Named Reactions and Structure Identification

Section: 22.5

Difficulty Level: Medium

25) What of the following reagents will permethylate a carbohydrate?

a) Acetone

b) CH₃OSO₃CH₃

c) H₂/Pd

d) Acetic anhydride

e) CH₃OH/HCl

Topic: Protecting Groups

Section: 22.5

Difficulty Level: Hard

26) Which of these compounds, I, II, III, IV, is a reducing disaccharide?

a) I alone

b) II alone

c) III alone

d) IV alone

e) I, II, III, and IV

Topic: Nomenclature, Definitions and Types of Carbohydrates

Section: 22.6

Difficulty Level: Easy

27) An aldaric acid is represented by:

a) I

b) II

c) III

d) IV

e) V

Topic: Nomenclature, Definitions and Types of Carbohydrates

Section: 22.6

Difficulty Level: Easy

28) An aldonic acid is represented by:

a) I

b) II

c) III

d) IV

e) V

Topic: Nomenclature, Definitions and Types of Carbohydrates

Section: 22.6

Difficulty Level: Easy

29) Which of these is a non-reducing monosaccharide?

a) I

b) II

c) III

d) IV

e) V

Topic: Nomenclature, Definitions and Types of Carbohydrates

Section: 22.6

Difficulty Level: Easy

30) Which compound will not reduce Ag(NH₃)₂⁺ ?

a) I

b) II

c) III

d) IV

e) V

Topic: Nomenclature, Definitions and Types of Carbohydrates

Section: 22.6

Difficulty Level: Easy

31) Consider the structures shown below. Which compound is not a reducing sugar?

a) I

b) II

c) III

d) IV

e) V

Topic: Nomenclature, Definitions and Types of Carbohydrates

Section: 22.6

Difficulty Level: Easy

32) Which of the following would give a positive test with Benedict's solution?

a) I

b) II

c) III

d) IV

e) All of these choices.

Topic: Reagents

Section: 22.6

Difficulty Level: Easy

33) Reaction of the following substance with bromine water would yield:

a) I

b) II

c) III

d) IV

e) V

Topic: Reactions

Section: 22.6

Difficulty Level: Easy

34) Consider the structures below. Which monosaccharides would yield an optically active aldonic acid when oxidized with bromine water?

a) I, II, and III

b) I, II, and V

c) III, IV, and VI

d) II, III, and IV

e) All of these choices.

Topic: Combination problems

Section: 22.6

Difficulty Level: Easy

35) Which of the following substances will afford a meso product upon reaction with Br₂/H₂O?

a) I

b) II

c) III and IV

d) II, III and IV

e) None of these choices.

Topic: Reactions

Section: 22.6

Difficulty Level: Medium

36) Which reagent would be used for the following transformation?

a) Ag(NH₃)₂⁺

b) HNO₃

c) Br₂/H₂O

d) HCl

e) Ag(NH₃)₂⁺ and Br₂/H₂O

Topic: Reagents

Section: 22.6

Difficulty Level: Easy

37) Which is an l-monosaccharide that would yield an optically active aldaric acid on oxidation by nitric acid?

a) I

b) II

c) III

d) II and IV

e) V

Topic: Stereochemical Considerations

Section: 22.6

Difficulty Level: Easy

38) Refer to the structures below. Which sugar(s) would yield an optically active aldaric acid on oxidation with nitric acid?

a) I and III

b) I, II, III, and V

c) II

d) III and IV

e) I and V

Topic: Combination problems

Section: 22.6

Difficulty Level: Easy

39) Reaction of the following substance with nitric acid would yield:

a) I

b) II

c) III

d) IV

e) V

Topic: Reactions

Section: 22.6

Difficulty Level: Easy

40) Which aldohexose would yield an optically active aldaric acid when treated with nitric acid?

a) I

b) II

c) III

d) IV

e) V

Topic: Reactions

Section: 22.6

Difficulty Level: Easy

41) Which of the following substances will afford an optically inactive product upon reaction with nitric acid?

a) I

b) II

c) III and IV

d) II, III and IV

e) All of these choices.

Topic: Reactions

Section: 22.6

Difficulty Level: Medium

42) What is the ratio of products formed by the reaction of periodic acid with the following compound?

H₂C=O HCO₂H CO₂

I 5 1 0

II 3 3 0

III 1 5 0

IV 1 4 1

V 0 4 2

a) I

b) II

c) III

d) IV

e) V

Topic: Product Ratios

Section: 22.6

Difficulty Level: Medium

43) What is the ratio of products formed by the reaction of periodic acid with the following compound?

H₂C=O HCO₂H CO₂

I 5 1 0

II 3 3 0

III 1 5 0

IV 2 3 1

V 0 4 2

a) I

b) II

c) III

d) IV

e) V

Topic: Product Ratios

Section: 22.6

Difficulty Level: Medium

44) A compound X reacts with 3 mol of HIO₄ to yield 2 mol of HCO₂H and 2 mol of HCHO. What is the structure of X?

a) I

b) II

c) III

d) IV

e) V

Topic: Reactions

Section: 22.6

Difficulty Level: Medium

45) If the methyl glycoside of an aldohexose is treated with HIO₄, one molar equivalent of HCHO is formed but no HCOOH. What size ring is present in the glycoside?

a) Three-membered

b) Four-membered

c) Five-membered

d) Six-membered

e) Seven-membered

Topic: Named Reactions and Structure Identification

Section: 22.4 and 22.6

Difficulty Level: Medium

46) Reaction of the following substance with sodium borohydride (NaBH₄) would yield:

a) I

b) II

c) III

d) IV

e) V

Topic: Reactions

Section: 22.7

Difficulty Level: Easy

47) Which reagent would be used for the following transformation?

a) NaBH₄

b) AgNO₃/C₂H₅OH

c) Br₂/CCl₄

d) HCl

e) Hot KMnO₄

Topic: Reagents

Section: 22.7

Difficulty Level: Easy

48) Refer to the following structures. Which d-aldohexose would react with NaBH₄ to yield an optically inactive alditol?

a) I

b) II

c) III

d) IV

e) V

Topic: Stereochemical Considerations

Section: 22.7

Difficulty Level: Medium

49) Sugars that would yield the same phenylosazone are:

a) I and II

b) II and III

c) I, II, and III

d) III and IV

e) I, II, and V

Topic: Named Reactions and Structure Identification

Section: 22.8

Difficulty Level: Easy

50) Consider the structures below. Which of the structures II-VI are epimers of I?

a) II

b) III and IV

c) IV

d) V

e) VI

Topic: Combination problems

Section: 22.8

Difficulty Level: Easy

51) Consider the structures above. Which monosaccharides would yield the same phenylosazone when treated with excess phenylhydrazine?

a) I and V

b) I and III

c) II and III

d) III and VI

e) IV and V

Topic: Combination problems

Section: 22.8

Difficulty Level: Easy

52) Refer to the structures below. Which sugars would react with phenylhydrazine to yield the same phenylosazone?

a) I and II

b) III and IV

c) I and V

d) II and III

e) III and V

Topic: Combination problems

Section: 22.8

Difficulty Level: Easy

53) Epimers are represented by:

a) I and II

b) II and III

c) I, II, and III

d) III and IV

e) I, II, and V

Topic: Nomenclature, Definitions and Types of Carbohydrates

Section: 22.8

Difficulty Level: Medium

54) Which of the following structures represent epimers?

a) I and II

b) III and V

c) III and IV

d) I and III

e) Pairs in more than one of these choices.

Topic: Stereochemical Considerations

Section: 22.8

Difficulty Level: Medium

55) Consider the structures below: what term(s) describe(s) the relationship between them?

a) Enantiomers

b) Epimers

c) Diastereomers

d) Anomers

e) More than one of these choices.

Topic: Stereochemistry

Section: 22.2 and 22.8

Difficulty Level: Easy

56) Sucrose reacts with which of these reagents?

a) C₆H₅NHNH₂

b) Cu²⁺

c) Br₂/H₂O

d) H₃O⁺

e) Ag(NH₃)₂⁺

Topic: Reagents

Section: 22.6 and 22.8

Difficulty Level: Easy

57) An unknown pentose Z reacts with NaBH₄ to give an optically inactive compound. The pentose Z gives the same osazone as arabinose. What carbohydrate is Z?

a) Fructose

b) Ribose

c) Xylose

d) Glucose

e) Lyxose

Topic: Reduction and Oxidation

Section: 22.7, 22.8

Difficulty Level: Medium

58) The Kiliani–Fischer synthesis is the reaction of an aldose with:

a) Br₂/H₂O; then HCN; then H₃O⁺; then Na-Hg, H₂O

b) HCN; then Ba(OH)₂; then H₃O⁺; then Na-Hg, H₂O

c) HCN; then H₃O⁺; then Ba(OH)₂; then Na-Hg, H₂O

d) Br₂/H₂O; then H₂O₂, Fe₂(SO₄)₃

e) Br₂/H₂O

Topic: Named Reactions and Structure Identification

Section: 22.9

Difficulty Level: Easy

59) The Ruff degradation is the reaction of an aldose with:

a) Br₂/H₂O; then HCN; then H₃O⁺; then Na-Hg, H₂O

b) HCN; then Ba(OH)₂; then H₃O⁺; then Na-Hg, H₂O

c) HCN; then H₃O⁺; then Ba(OH)₂; then Na-Hg, H₂O

d) Br₂/H₂O; then H₂O₂, Fe₂(SO₄)₃

e) Br₂/H₂O

Topic: Named Reactions and Structure Identification

Section: 22.9

Difficulty Level: Easy

60) A d-aldohexose X, is subjected to a Ruff degradation. The degradation product is treated with nitric acid to yield an optically inactive aldaric acid. A possible structure for X is:

a) I

b) II

c) III and IV

d) IV

e) II and V

Topic: Reactions

Section: 22.9

Difficulty Level: Medium

61) A d-aldohexose, Z, is subjected to a Ruff degradation. The degradation product is treated with nitric acid to yield an optically active aldaric acid. A possible structure for Z is:

a) I

b) II

c) III

d) IV

e) I, IV

Topic: Reactions

Section: 22.9

Difficulty Level: Medium

62) Consider the structure of d-allose below:

Which of the following structures represents l-allose?

a) I

b) II

c) III

d) IV

e) V

Topic: Combination problems

Section: 22.10

Difficulty Level: Easy

63) Which compound is d-galactose?

a) I

b) II

c) III

d) IV

e) V

Topic: Nomenclature, Definitions and Types of Carbohydrates

Section: 22.10

Difficulty Level: Medium

64) Which compound or compounds would be formed when d-glucose is dissolved in methanol and then treated with anhydrous acid?

a) I

b) II

c) III

d) IV

e) I and IV

Topic: Reactions

Section: 22.4 and 22.10

Difficulty Level: Medium

65) Which is not an intermediate monosaccharide in the Kiliani–Fischer synthesis of d-mannose from d-glyceraldehyde?

a) d-Ribose

b) d-Threose

c) d-Arabinose

d) d-Erythrose

e) d-Ribose and d-Threose

Topic: Named Reactions and Structure Identification

Section: 22.9 and 22.10

Difficulty Level: Easy

66) Which of the following would yield d-glucose and d-mannose when subjected to a Kiliani–Fischer synthesis?

a) I

b) II

c) III

d) IV

e) V

Topic: Reactions

Section: 22.9 and 22.10

Difficulty Level: Medium

67) An aldopentose, X, is subjected to a Kiliani–Fischer synthesis to produce two aldohexoses, Y and Z. Both Y and Z, when oxidized with nitric acid, yield optically active aldaric acids. Which structure represents X?

a) I

b) II

c) III

d) IV

e) V

Topic: Named Reactions and Structure Identification

Section: 22.9 and 22.10

Difficulty Level: Medium

68) Consider the structures below. An l-aldohexose, X, is treated with nitric acid to yield an optically inactive aldaric acid. The same l-aldohexose, X, is subjected to a Ruff degradation and the degradation product is oxidized with nitric acid to produce an optically inactive aldaric acid. Which is a possible structure for X?

a) I

b) II

c) III

d) IV

e) V

Topic: Combination problems

Section: 22.6, 22.9 and 22.10

Difficulty Level: Easy

69) Refer to the following structures. Which aldohexose when subjected to Fischer's end-group interchange would be converted to a compound identical with itself?

a) I

b) II

c) III

d) IV

e) V

Topic: Stereochemical Considerations

Section: 22.11

Difficulty Level: Easy

70) The d-glucose unit at the branching point of amylopectin has free hydroxyl groups at which positions?

a) C2, C3, and C6

b) C2 and C3

c) C3 and C4

d) C3, C4, and C6

e) C4 and C6

Topic: General Information

Section: 22.12

Difficulty Level: Easy

71) Which of these is an example of a glucan?

a) Maltose

b) Sucrose

c) Lactose

d) Cellobiose

e) Amylose

Topic: Nomenclature, Definitions and Types of Carbohydrates

Section: 22.12

Difficulty Level: Medium

72) Compound X is a reducing sugar which, on hydrolysis, affords two molar equivalents of d-glucose. This hydrolysis is catalyzed by an enzyme specific for glucosides of this type:

What is the identity of X?

a) Sucrose

b) Lactose

c) Maltose

d) Cellobiose

e) None of these choices.

Topic: Named Reactions and Structure Identification

Section: 22.6 and 22.12

Difficulty Level: Easy

73) Which is a reducing sugar with an α-glycosidic linkage?

a) Sucrose

b) Maltose

c) Lactose

d) Cellobiose

e) Glucose

Topic: Nomenclature, Definitions and Types of Carbohydrates

Section: 22.2, 22.6 and 22.12

Difficulty Level: Medium

74) Which monosaccharide is recovered from the hydrolysis of starch?

a) d-Galactose

b) d-Gulose

c) d-Glucose

d) Cellobiose

e) Maltose

Topic: Reactions

Section: 22.13

Difficulty Level: Easy

75) Which monosaccharide is recovered from the hydrolysis of glycogen?

a) d-Galactose

b) d-Glucose

c) d-Gulose

d) Cellobiose

e) Maltose

Topic: Reactions

Section: 22.13

Difficulty Level: Easy

76) Cellulose lacks nutritive value for humans because:

a) the products of its digestion are excreted without utilization.

b) its conformation prevents attack by digestive enzymes.

c) we lack the enzymes which can catalyze the hydrolysis of the glycosidic linkages.

d) it passes through the digestive tract so rapidly.

e) the molecules possess such a high molecular weight that enzymes can not hydrolyze it.

Topic: General Information

Section: 22.13

Difficulty Level: Easy

77) What is “gun cotton”?

a) Cellulose trinitrate

b) Cellulose acetate

c) Cellulose xanthate

d) Amilose acetate

e) Maltose trinitrate

Topic: Polysaccarides

Section: 22.13

Difficulty Level: Easy

78) Which of the following is the structure of d-galacturonic acid?

a) I

b) II

c) III

d) IV

e) V

Topic: Nomenclature, Definitions and Types of Carbohydrates

Section: 22.14

Difficulty Level: Easy

79) What is an amino sugar?

a) A sugar that bears substituted with an amino acid on the anomeric OH group.

b) An amino acid with a side chain as a sugar.

c) A sugar where the anomeric OH group is substituted by an ammonium group.

d) A sugar where a non-anomeric OH group is replaced by an amino group.

e) An amino acid replacing an OH group on a sugar.

Topic: Amino Sugars

Section: 22.15

Difficulty Level: Easy

80) Complete hydrolysis of heparin gives:

a) -N-Acetylmuramic acid and -d-glucosamine.

b) -d-Glucosamine and glucuronate-2-sulfate.

c) d-Glucuronate-2-sulfate and N-sulfo-3-glucosamine-6-sulfate.

d) Glucose sulfate and maltose.

e) Chitin and d-glucurunate-2-sulfate.

Topic: Amino Sugars

Section: 22.15

Difficulty Level: Easy

81) Cellulose differs from chitin in which way?

a) Cellulose has -glycosidic linkages; chitin has -glycosidic linkages.

b) Cellulose contains only d-glucose units; chitin contains only N-acetyl-d-glucosamine units.

c) Cellulose cannot be hydrolyzed; chitin can be hydrolyzed.

d) Cellulose has a linear structure; chitin has a helical structure.

e) Cellulose chains are branched; chitin chains are unbranched.

Topic: General Information

Section: 22.13 and 22.15

Difficulty Level: Medium

82) One of the monosaccharides that form part of sialyl Lewis^x acids is:

a) Glucosamine

b) Chitin

c) Galactosamine

d) Glucaric acid

e) Heparin

Topic: Amino Sugars

Section: 22.16

Difficulty Level: Easy

83) Streptomycin is:

a) A lipid antibiotic

b) A carbohydrate antibiotic

c) An antigen

d) An antibody

e) A glycoprotein

Topic: Carbohydrate Antibiotic

Section: 22.17

Difficulty Level: Easy

84) The activity of streptomycin is due to:

a) Disruption of carbohydrate synthesis in bacteria

b) Disruption of bacterial division

c) Formation of blood clots

d) Disruption of bacterial protein synthesis

e) Hydrolysis of bacterial cell wall

Topic: Carbohydrate Antibiotic

Section: 22.17

Difficulty Level: Easy

Question type: Fill-in-the-blank

85) The simplest carbohydrates (those that cannot be hydrolyzed to simpler carbohydrates) are called ____.

Topic: General Information

Section: 22.1

Difficulty Level: Easy

86) Carbohydrates that hydrolyze to give a large number of molecules of monosaccharides are called ___.

Topic: General Information

Section: 22.1

Difficulty Level: Easy

Question type: Essay

87) If human were able to completely hydrolyze paper, wood or cotton in their digestive system, could humans get fat? Why?

Topic: General Information

Section: 22.1

Difficulty Level: Easy

Question type: fill-in-the-blank

88) Carbohydrates are synthesized in green plants by ___.

Topic: General Information

Section: 22.1

Difficulty Level: Easy

89) A monosaccharide containing six carbon atoms and an aldehyde functionality is called a(n) ___.

Topic: General Information

Section: 22.2

Difficulty Level: Easy

90) Many carbohydrates exist in equilibrium with cyclic hemiacetals. Those carbohydrates that form a five-membered cyclic hemiacetal are called ___.

Topic: General Information

Section: 22.2

Difficulty Level: Easy

Question type: Essay

91) α-d-Glucose has [α]_D = +112, and β-d-glucose has [α]_D = +19. If either anomer is dissolved in water and allowed to reach equilibrium, the specific rotation of the solution is +52. What are the percentages of each anomer at equilibrium?

Percentage of the β-anomer at equilibrium:

Percentage of the α-anomer at equilibrium: 100 – 64.5 = 35.5%

Topic: Mutarotation

Section: 22.3

Difficulty Level: Medium

92) Lactose exists in two forms α and β. Anomer α has [α]_D = +92.6, and anomer β has [α]_D = +34. What are the percentages of each anomer at equilibrium when the specific rotation of the water solution is +52?

Percentage of the α-anomer at equilibrium: 100% – 69% = 31%.

Topic: Mutarotation

Section: 22.3

Difficulty Level: Medium

93) Many other sugars besides glucose exhibit mutarotation. For example, α-d-galactopyranose has [α]_D = +150.7, and β-d-galactopyranose has [α]_D = +52.8. Show how the equilibrium percentages of α and β anomers can be calculated from the equilibrium specific rotation of +80.2.

Percentage of the anomer α at equilibrium: 100% – 72% = 28%

Topic: Mutarotation

Section: 22.3

Difficulty Level: Medium

94) What is the mechanism of the hydrolysis of maltose to glucose under acidic conditions?

Topic: Reactions

Section: 22.4

Difficulty Level: Hard

95) Define each of the following:

a) aldohexose

b) mutarotation

c) glycoside

d) polysaccharides

e) d-sugars

b) Mutarotation occurs by a reversible ring opening of each anomer to the open-chain aldehyde, followed by reclosure.

c) Glycoside is a carbohydrate acetal, obtained in the reaction of a monosaccharide hemiacetal with an alcohol under acidic conditions.

d) Polysaccharides are carbohydrates in which tens, hundreds, or even thousands of simple sugars are linked together through glycoside bonds.

e) d-Sugars have the hydroxyl group at the lowest chiral carbon atom on the right in Fischer projection.

Topic: Nomenclature, Definitions and Types of Carbohydrates

Section: 22.1, 22.2, 22.3 and 22.4

Difficulty Level: Easy

96) What is the structure for A?

Topic: Reactions

Section: 22.5

Difficulty Level: Medium

97) Sugars that give positive tests with Benedict's or Tollens' solution are called ___.

Topic: General Information

Section: 22.6

Difficulty Level: Easy

98) Bromine water is a reagent that converts an aldose to an ___.

Topic: General Information

Section: 22.6

Difficulty Level: Easy

99) Draw the structure(s) of the -lactone(s) that can be formed from d-Glucaric acid.

Topic: Aldaric Acids

Section: 22.6

Difficulty Level: Medium

100) Consider the structure of d-erythrose, shown below. Draw the structure of the product obtained upon treatment of d-erythrose with nitric acid. Give its IUPAC name and comment on its stereochemistry.

d-erythrose 2,3-dihydroxybutanedioic acid

(meso)

Topic: Aldaric Acids

Section: 22.6

Difficulty Level: Medium

101) Complete the following reaction:

Topic: Reagents

Section: 22.6

Difficulty Level: Easy

102) What products are expected from the reaction of 3-hydroxy-2,4-pentanedione with 2 molar equivalents of periodic acid?

Topic: Periodate Oxidations

Section: 22.6

Difficulty Level: Medium

103) Suggest a simple chemical test that you might use to distinguish between 2,3-pentanediol and 2,4-pentanediol?

Topic: Periodate Oxidations

Section: 22.6

Difficulty Level: Medium

104) Provide the structures of the d-series that would give optically inactive alditols.

Topic: Reduction

Section: 22.7

Difficulty Level: Medium

105) Complete the reaction and give the structure and name of the product(s):

Topic: Reactions

Section: 22.7

Difficulty Level: Medium

106) Draw structures for 3 different epimers of d-glucose.

Topic: Epimers

Section: 22.8

Difficulty Level: Easy

107) The method of lengthening the carbon chain of an aldose through the addition of HCN followed by hydrolysis and reduction is called the ___.

Topic: General Information

Section: 22.9

Difficulty Level: Easy

108) What products are expected to be formed upon subjecting l-erythrose (shown below) to the following reaction sequence? (Draw Fischer projection formulas)

i) HCN; ii) Ba(OH)₂; iii) H₃O⁺; iv) Na(Hg), H₂O, pH 3-5

Topic: Kiliani Fischer Synthesis

Section: 22.9

Difficulty Level: Medium

109) What products are expected to be formed upon subjecting d-galactose (shown below) to the following reaction sequence? (Draw Fischer projection formulas.)

i) Br₂, H₂O; ii) H₂O₂, Fe₂(SO₄)₃

Topic: Ruff degradation

Section: 22.9

Difficulty Level: Medium

110) An optically active hexose (A), C₆H₁₂O₆, was degraded to an optically active pentose (B), C₅H₁₀O₅, by the following series of reactions:

Compound (B) was degraded to an optically active tetrose (C), C₄H₈O₄, through the same series of reactions as shown above; then (C) was oxidized with HNO₃ to yield meso tartaric acid.

Give possible structure for (A) and (B).

Topic: Reactions

Section: 22.6 and 22.9

Difficulty Level: Hard

111) Draw the most stable chair conformation of α-d-mannopyranose.

Topic: Structure Identification

Section: 22.2 and 22.10

Difficulty Level: Medium

112) Provide the structure of d-mannose in Haworth projection.

Topic: Structure Identification

Section: 22.2 and 22.10

Difficulty Level: Medium

113) Provide the structure of ethyl α-d-mannoside in Haworth projection.

Topic: Structure Identification

Section: 22.2, 22.4 and 22.10

Difficulty Level: Medium

114) When naturally occurring aldotetrose A is reduced with sodium borohydride, meso-1,2,3,4-butanetetrol is formed. What are the name and structure of A?

Topic: Reactions

Section: 22.7 and 22.10

Difficulty Level: Easy

115) What are the names of the following structures?

a) d-xylonic acid

b) d-xylaric acid

c) d-xylitol

d) d-xylose phenylosazone

Topic: Nomenclature, Definitions and Types of Carbohydrates

Section: 22.6, 22.7, 22.8 and 22.10

Difficulty Level: Medium

116) Name each of the following compounds:

a) d-galactonic acid

b) d-galactaric acid

c) d-galactitol

d) d-galactose phenylosazone

Topic: Nomenclature, Definitions and Types of Carbohydrates

Section: 22.6, 22.7, 22.8 and 22.10

Difficulty Level: Medium

117) Upon treatment of d-glucose with HNO₃ an optically active aldaric acid is produced. Based on this result, what two structures could be discarded as being d-glucose? Draw their structure.

Topic: Structural Analysis

Section: 22.11

Difficulty Level: Medium

118) Ordinary table sugar is a disaccharide called ___.

Topic: General Information

Section: 22.12

Difficulty Level: Easy

119) Milk contains a disaccharide called ___.

Topic: General Information

Section: 22.12

Difficulty Level: Easy

120) Which disaccharide(s) (sucrose, maltose, cellobiose, and lactose)

a) are α-glucosides?

b) is a β-galactoside?

c) reduce Fehling’s solution?

d) gives invert sugar?

e) form osazones and exhibit mutarotation?

b) Lactose

c) Maltose and lactose

d) Sucrose

e) Maltose and lactose.

Topic: General Information

Section: 22.12

Difficulty Level: Medium

121) Why can cellulose not serve as a food source for humans?

Topic: General Information

Section: 22.13

Difficulty Level: Easy

122) What is the structural feature that makes amylose exhibit a helical structure and cellulose exhibit a rigid linear structure?

Topic: Structure

Section: 22.13

Difficulty Level: Easy

123) A polysaccharide found in the shells of lobsters, crabs, and in the exoskeletons of insects and spiders is called ___.

Topic: General Information

Section: 22.15

Difficulty Level: Easy

124) What is the structural similarity between chitin and cellulose?

Topic: Polysaccharide

Section: 22.15

Difficulty Level: Easy

125) What are NOT carbohydrates?

a) I, II, III

b) I, V

c) II, III

d) I, II, III, IV

e) III, IV

Topic: General

Section: 22.1

Difficulty Level: Easy

126) Refer to the structures below. Which are D-sugars?

a) II and IV

b) I, II, and III

c) I and V

d) III, IV, and V

e) IV and V

Topic: Combination problems

Section: 22.2

Difficulty Level: Easy

127) Refer to the structures below. Which are D-sugars?

a) I, II, and IV

b) II and V

c) I, II, III, and IV

d) V

e) IV and V

Topic: Stereochemical Considerations

Section: 22.2

Difficulty Level: Medium

128) Refer to the structures below. Which are L-sugars?

a) I, II, and IV

b) II and V

c) I, II, III, and IV

d) V

e) IV and V

Topic: Stereochemical Considerations

Section: 22.2

Difficulty Level: Medium

129) Which of these is -d-glucopyranose?

a) I

b) II

c) III

d) IV

e) V

Topic: Nomenclature, Definitions and Types of Carbohydrates

Section: 22.2

Difficulty Level: Medium

130) Which would NOT undergo mutarotation in neutral aqueous solution?

a) I

b) II

c) III

d) IV

e) I, II and III

Topic: Stereochemical Considerations

Section: 22.3

Difficulty Level: Medium

131) Consider the structures shown below. Which structure represents -d-glucopyranose?

a) I

b) II

c) III

d) IV

e) V

Topic: Nomenclature, Definitions and Types of Carbohydrates

Section: 22.3

Difficulty Level: Medium

132) Which of these is NOT a glycoside?

a) I, II, and III

b) III and IV

c) I, II, III, and V

d) II, IV, and V

e) III, IV, and V

Topic: Nomenclature, Definitions and Types of Carbohydrates

Section: 22.4

Difficulty Level: Easy

133) Which of these compounds is NOT a reducing disaccharide?

a) I alone

b) II and IV

c) III alone

d) IV alone

e) I, III, and IV

Topic: Nomenclature, Definitions and Types of Carbohydrates

Section: 22.6

Difficulty Level: Easy

134) Which of the following is the structure of L-galacturonic acid?

a) I

b) II

c) III

d) IV

e) V

Topic: Nomenclature, Definitions and Types of Carbohydrates

Section: 22.14

Difficulty Level: Easy