Deck 10: Carbohydrates

Question 1

What is the classification of this monosaccharide?

A) aldotriose
B) ketotriose
C) aldotetrose
D) ketotetrose

Answer 1

aldotetrose

Question 2

What is the classification of this monosaccharide?

A) aldopentose
B) aldohexose
C) ketopentose
D) ketohexose

Answer 2

ketohexose

Question 3

An aldose is a carbohydrate that contains

A) hydroxy groups on the terminal carbons.
B) water molecules on the alpha carbon.
C) an aldehyde group.
D) monosaccharides.

Answer 3

an aldehyde group.

Question 4

How would this compound be classified?

A) carboxylic carbohydrate
B) hydroxyaldehyde
C) ketotriose
D) aldotriose

Question 5

Choose the compound that is a ketotetrose.

A)
B)
C)
D)

Question 6

Which of the following properties of an enantiomer does not influence the amount of its rotation of plane polarized light?

A) temperature
B) wavelength of light
C) number of molecules that the light passes through
D) its chemical property

Question 7

Which of the following is an L monosaccharide?

A)

B)

C)

D)

Question 8

Which of the following molecules contain a chiral carbon?

A)
B)
C)
D)

Question 9

Which of the following molecules contain a chiral carbon?

A)
B)
C)
D)

Question 10

How many chiral carbons are present in the structure below?

A) 2
B) 3
C) 4
D) 5

Question 11

The structure of the compound 2,3,4-trihydroxybutanal is shown below. How many stereoisomers are possible for this molecule?

A) 2
B) 4
C) 8
D) 16

Question 12

The structural formula for erythrose is drawn here. The carbon atoms are numbered from the carbonyl group.

A) This is the only formula for erythrose; there are no stereoisomers.
B) This is both a D and an L structure, as determined by carbons 1 and 2.
C) This is D-erythrose, as determined by carbon 3.
D) This is L-erythrose, as determined by carbon 4.

Question 13

How many stereoisomers would a carbohydrate with 5 chiral carbons have?

A) 5 stereoisomers
B) 20 stereoisomers
C) 32 stereoisomers
D) 60 stereoisomers

Question 14

What is the relationship of these compounds to each other?

A) Compounds II and III are enantiomers; compound I is not related to II and III.
B) Compounds I and II are enantiomers; III is a diastereomer of I and II.
C) Compounds I and II are enantiomers; compound III is not related to I and II.
D) These three compounds are not related to each other; they only look similar.

Question 15

What can be said about the relationship of these two carbohydrates?

A) These two structures are not related.
B) Both have four chiral carbons.
C) They are superimposable.
D) They are enantiomers.

Question 16

Which of the following is a deoxy sugar?

A)
B)
C)
D)

Question 17

Which of the following is an alcohol sugar?

A)
B)
C)
D)

Question 18

Which of the following is a carboxylic acid sugar?

A)
B)
C)
D)

Question 19

Which of the following is an amino sugar?

A)
B)
C)
D)

Question 20

Which are the most commonly found monosaccharides in nature?

A) those with 4 carbons
B) those with 5-6 carbons
C) those with 7-9 carbons
D) those with 10 or more carbons

Question 21

D-glucose is often called by other names, such as corn sugar and grape sugar. It is also referred to as ___.

A) dextrose
B) fruit sugar
C) blood sugar
D) dextrose and blood sugar

Question 22

Fructose is different from glucose and galactose because

A) fructose is a pentose; the other sugars are hexoses.
B) fructose is a ketose; the other sugars are aldoses.
C) the cyclic form is a square; the other sugars display hexagons.
D) fructose doesn't have an open form; the other sugars do have an open form.

Question 23

Which of the following is an aldonic acid?

A)
B)
C)
D)

Question 24

Which of the following is a uronic acid?

A)
B)
C)
D)

Question 25

Benedict's reagent is used for detecting reducing sugars because

A) a reduction of the sugar occurs producing an acid.
B) the aldehyde group in the sugar is oxidized.
C) the copper ion in the reagent is oxidized as the sugar is reduced.
D) the -OH groups are exchanged for hydrogens.

Question 26

What is the product of the following reaction?

A)
B)
C)
D)

Question 27

What is the product of the following reaction?

A)
B)
C)
D)

Question 28

Which are anomers?

A) aldotetrose and ketotetrose
B) D-glucose and L-glucose
C) glucopyranose and glucofuranose
D) $\alpha$ -D-galacose and $\beta$ -D-galactose

Question 29

What is mutarotation?

A) The conversion of a D-monosaccharide into an L-monosaccharide.
B) The conversion of $\alpha$ -D-galacose into $\beta$ -D-galactose.
C) The conversion of a pyranose into a furanose.
D) The conversion of an aldose into a ketose.

Question 30

Shown below is a cyclic form of D-galactose. This structure is classified as ___.

A) $\alpha$ -D-galactopyranose
B) $\beta$ -D-galactofuranose
C) $\alpha$ -D-galactofuranose
D) $\beta$ -D-galactopyranose

Question 31

Shown below is a cyclic form of D-mannose. This structure is classified as ___.

A) $\alpha$ -D-mannopyranose
B) $\beta$ -D-mannofuranose
C) $\alpha$ -D-mannofuranose
D) $\beta$ -D-mannopyranose

Question 32

Shown below is a cyclic form of D-Fructose. This structure is classified as ___.

A) $\alpha$ -D-fructopyranose
B) $\beta$ -D-fructopyranose
C) $\beta$ -D-fructofuranose
D) $\alpha$ -D-fructofuranose

Question 33

Shown below is a cyclic form of D-glucose. This structure is classified as ___.

A) $\alpha$ -D-glucopyranose
B) $\beta$ - D-glucofuranose
C) $\alpha$ -D-galactopyranose
D) $\beta$ - L-glucopyranose

Question 34

What is the name of this compound?

A) $\alpha$ -D-ribofuranose
B) $\alpha$ -D-2-deoxyribofuranose
C) $\alpha$ -D-3-deoxyribofuranose
D) -D-ribose

Question 35

What is the name of this carbohydrate?

A) -D-aminogalactose
B) 11ef9a7a_2ac8_6bf8_b674_499d636a6548_TB10109_00 $\alpha$ -D-galactosaminofuranose
C) $\alpha$ -D-galactosaminopyranose
D) 11ef9a7a_2ac8_6bf8_b674_499d636a6548_TB10109_00-D-galactosaminopyranose

Question 36

Which of the following can be obtained from hydrolysis of simple glycosides?

A) Alcohol
B) Ester
C) Ether
D) amine

Question 37

Maltose is hydrolyzed by the enzyme maltase into two molecules of glucose. Maltose is classified as a ___.

A) onosaccharide
B) disaccharide
C) cellulose
D) polysaccharide

Question 38

Oligosaccharides are digested in the ___.

A) stomach
B) intestines
C) mouth
D) blood plasma

Question 39

Sucrose is a disaccharide of D-glucose connected to D-fructose by an $\alpha$ , $\beta$ -(1 $\rightarrow$ 2)- glycosidic bond. Sucrose is not a reducing sugar because

A) it is a disaccharide.
B) it reacts with Benedict's solution.
C) it contains both glucose and fructose.
D) it cannot react to produce an aldehyde group.

Question 40

Relative sweetness is a measure of the sweetness of any chosen sweetener compared to that of

A) invert sugar.
B) the sweetest carbohydrate, fructose.
C) sucrose.
D) saccharin.

Question 41

The disaccharides are important in nature; a few examples of disaccharides are

A) D-abqueose, D-fructose, galactose, and glucose.
B) raffinose, stachyose, and verbascose.
C) cellobiose, lactose, maltose, and sucrose.
D) amylopectin, amylose, and starch.

Question 42

Glycogen and amylopectin are similar in that they are both polymers of glucose. Glycogen is the glucose storage form for ___ and starch is the glucose storage form for ___.

A) plants/plants
B) animals/animals
C) plants/animals
D) animals/plants

Question 43

___ is the structural material for plants while ___ is the energy storage material of plants.

A) Cellulose/starch
B) Starch/cellulose
C) Glycogen/starch
D) Starch/glycogen

Question 44

The carbohydrates which contain the largest molecules are the

A) monosaccharides.
B) polysaccharides.
C) oligosaccharides.
D) aldohexoses.

Question 45

___ is the energy storage polysaccharide of plants and ___ is the energy storage polysaccharide for animals.

A) Cellulose/starch
B) Starch/cellulose
C) Glycogen/starch
D) Starch/glycogen

Question 46

Starch and cellulose are both polysaccharides of glucose. Cellulose differs from starch in that

A) cellulose contains glucose molecules connected by $\alpha$ - (1 $\rightarrow$ 4) glycosidic bonds.
B) cellulose contains glucose molecules connected by $\beta$ - (1 $\rightarrow$ 4) glycosidic bonds.
C) cellulose is more highly branched than starch.
D) cellulose is the energy storage molecule of plants.

Question 47

Starch contains two polymers of glucose, they are amylose and amylopectin. Amylose differs from amylopectin in that

A) amylopectin contains fructose and amylose does not.
B) amylose contains fructose and amylose does not.
C) amylose is highly branched and amylopectin is not.
D) amylopectin is highly branched and amylose is not.

Question 48

Chose the incorrect statement referring to starches.

A) Starches are produced by plants for the storage of energy.
B) Starch is composed of two homopolysaccharides-amylose and amylopectin.
C) Starch forms helical shapes, rather than forming up in sheets of polysaccharides.
D) Starches are the structural material of animal cells.

Question 49

Hyaluronic acid solutions serve as lubricants in the fluid of joints and are present in the vitreous humor of the eye. A portion of its structure is shown below.
Which of the following statements is true?

A) Hyaluronic acid is a homopolysaccharide.
B) Hyaluronic acid is a heteropolysaccharide.
C) Hyaluronic acid is made of D-glucose residues.
D) The monosaccharide residues in hyaluronic acid are of furanose form.

Question 50

The method to determine the number of stereoisomers of a monosaccharide is to calculate 2ⁿ, where n is the total number of carbons in the molecule.

Question 51

A pair of compounds are stereoisomers and they are nonsuperimposable mirror images. This pair of isomers is referred to as a pair of enantiomers.

Question 52

$\alpha$ -D-glucose and -D-glucose are anomers.

Question 53

A drug's enantiomers can be responsible for the desired physiologic effects, while the other enantiomer is less active, inactive, or sometimes even responsible for adverse effects.

Question 54

A racemic mixture can rotate a plane-polarized light in a clockwise direction.

Question 55

In deoxy sugars a hydrogen atom replaces one or more of the -OH groups in a monosaccharide.

Question 56

Mutarotation is an enzyme-catalyzed process by which a pyranose is changed into a furanose.

Question 57

Oligosaccharides contain 2-10 monosaccharide residues.

Question 58

Maltose is a monosaccharide

Question 59

Both starch and cellulose are polysaccharides of glucose.

Question 60

Blood type is determined by oligosaccharides attached to the surface of red blood cells.

Question 61

Cellulose is composed of glucose molecules connected by $\alpha$ -glycosidic linkages.

Question 62

Glycogen contains $\alpha$ -1,4- and $\alpha$ -1,6-glycosidic bonds.

Question 63

carbohydrate containing six carbons is broadly referred to as a(an) ___.

Question 64

A monosaccharide has an aldehyde functional group as well as five carbon atoms. This monosaccharide is a(n) ___.

Question 65

In a D sugar, the -OH on the highest numbered chiral carbon in a Fischer projection points to the ___.

Question 66

In sugar chemistry, diastereomers that differ at only one chiral carbon atom are called ___.

Question 67

Monosaccharides that react with Benedict's solution are known as ___ sugars.

Question 68

Monosaccharides that form anomers containing five -membered rings are called ___.

Question 69

Alpha and beta anomers can interconvert by a process known as ___.

Question 70

A pyranose is composed of a ___-membered ring.

Question 71

Acetals formed between $\alpha$ or $\beta$ monosaccharide anomers and alcohols are called ___ and the bond that connects the acetal carbon to the newly added -OC group is called a ___.

Question 72

Even though maltose is an animal product and cellobiose is produced by plants, both carbohydrates produce ___ molecules when hydrolyzed.

Question 73

A molecule humans produce by combining glucose molecules for energy storage is ___.

Question 74

The enzyme ___ in saliva begins the digestion of starch.

Question 75

Shown below is a Fisher projection of galactose.

-Is the galactose structure shown above a D or an L sugar?

Question 76

Sketch the structure of the product formed when galactose is reduced by H₂ and Pt.

Question 77

Sketch the structure of the product formed when carbon 1 of galactose is oxidized by Benedict's solution.

Question 78

What is the structural difference between $\alpha$ -D-galactopyranose and $\alpha$ -D-glucopyranose?

Question 79

Why can't humans digest cellulose, but can digest starch?

Question 80

Explain why starch is a source of food while cellulose is a source of fiber in the human diet.