Carbohydrate Test

b) starch and glycogen

In which of the following pairs of carbohydrates are both members of the pair polysaccharides? a) cellulose and cellobiose b) starch and glycogen c) amylose and lactose d) more than one correct response e) no correct response

b) cellulose

In which of the following polysaccharides are all glycosidic linkages of the (1,4) type? a) starch b) cellulose c) glycogen d) amylopectin

d) sucrose

In which of the following sugars is the bonding between monosaccharide units "head-to head" rather than "head-to-tail"? a) cellobiose b) maltose c) lactose d) sucrose

d) more than one correct response

The left- and right-handed forms of a monosaccharide with a single chiral center are a) enantiomers. b) diastereomers. c) epimers. d) more than one correct response e) no correct response

c) linkages between the monosaccharide units present.

The major structural difference between cellulose and starch is found in the a) identity of the monosaccharide units present. b) ring size of the monosaccharide units present. c) linkages between the monosaccharide units present. d) handedness of the monosaccharide units present.

c) carbon #4

The structure of D-galactose differs from that of D-glucose at which carbon atom? a) carbon #2 b) carbon #3 c) carbon #4 d) carbon #5

A positive Tollen's test classifies a monosaccharide as a reducing sugar. T/F

True

All cyclic monosaccharides can exist in alpha- and beta-configurations. T/F

True

All monosaccharides are either aldoses and ketoses. T/F

True

Both amylopectin and glycogen are branched glucose polymers. T/F

True

Cellulose and amylose are glucose polymers which differ in the type of glycosidic linkage present. T/F

True

Complete hydrolysis of a oligosaccharide produces only monosaccharides. T/F

True

Complete hydrolysis of both maltose and cellobiose produce the same molecule. T/Fq

True

Cyclic forms of aldoses result from intermolecular hemiacetal formation. T/F

True

Enantiomers can never be epimers. T/F

True

Mirror images of an achiral molecule are identical. T/F

True

Monosaccharides cannot be broken done into simpler units by hydrolysis reactions. T/F

True

Reaction of an alcohol with a cyclic monosaccharide produces a glycoside. T/F

True

The "highest-numbered" chiral center in a monosaccharide is used to determine D- or L-configuration. T/F

True

The bond which links the two monosaccharides of a disaccharide together is a carbon-oxygen-carbon bond. T/F

True

The term sugar is a general designation for both monosaccharides and disaccharides. T/F

True

There can never be more than two enantiomers for a molecule. T/F

True

a) galactose

Which of the following carbohydrates will give a positive Benedict's test? a) galactose b) sucrose c) starch d) more than one correct response e) no correct response

C

Which of the following compounds is both an aldose and a hexose?

a) sucrose

Which of the following disaccharides does not have two cyclic forms (alpha and beta)? a) sucrose b) lactose c) maltose d) more than one correct response e) no correct response

b) sucrose

Which of the following disaccharides produces two different monosaccharides upon hydrolysis? a) maltose b) sucrose c) cellobiose d) more than one correct response e) no correct response

b) homopolysaccharide and chitin

Which of the following is a correct pairing of terms? a) heteropolysaccharide and starch b) homopolysaccharide and chitin c) branch-chain polysaccharide and cellulose d) unbranched-chain polysaccharide and glycogen

e) no correct response

Which of the following is a correct pairing of terms? a) storage polysaccharide and cellulose b) structural polysaccharide and starch c) acidic polysaccharide and glycogen d) more than one correct response e) no correct response

c) sucrose

Which of the following is not a reducing sugar? a) fructose b) glucose c) sucrose d) lactose

a) glucose

Which of the following monosaccharides are aldohexoses? a) glucose b) fructose c) ribose d) more than one correct response e) no correct response

c) glucose

Which of the following monosaccharides has a structure in which two or more chiral centers are present? a) glyceraldehyde b) dihydroxyacetone c) glucose d) more than one correct response e) no correct response

D

Which of the following monosaccharides has an open chain form that is a ketose?

b) galactose

Which of the following monosaccharides has cyclic forms that involve a 6-membered ring? a) fructose b) galactose c) ribose d) more than one correct response e) no correct response

c) melting point

Which of the following properties would be the same for D-galactose and L-galactose? a) interaction with plane polarized light b) solubility in a chiral solvent c) melting point d) reaction with (+)-2,3-butanediol

d) more than one correct response

Which of the following properties would be the same for a pair of enantiomeric monosaccharides? a) interaction with plane-polarized light b) boiling point c) solubility in water d) more than one correct response e) no correct response

b) They are all polyhydroxy aldehydes, polyhydroxyketones, or substances that yield such upon hydrolysis.

Which of the following statements concerning carbohydrates is correct? a) They are the most abundant type of biochemical substance in the human body. b) They are all polyhydroxy aldehydes, polyhydroxyketones, or substances that yield such upon hydrolysis. c) They can exist in left-handed and right-handed forms, with the left-handed form being dominant in nature. d) They all have a sweet taste and therefore are also called sugars.

b) Dihydroxyacetone has two chiral centers.

Which of the following statements concerning chiral centers in specific monosaccharides is incorrect? a) Glyceraldehyde has one chiral center. b) Dihydroxyacetone has two chiral centers. c) Fructose has three chiral centers. d) Glucose has four chiral centers.

c) They are enantiomers.

Which of the following statements concerning the D- and L- forms of a monosaccharide is incorrect? a) They have structures that are nonsuperimposable mirror images of each other. b) They must contain the same number of chiral centers. c) They are enantiomers. d) more than one correct response e) no correct response

e) no correct response

Which of the following statements concerning the positioning of -OH groups in the Fischer projection for L-glucose is correct? a) right on both carbons 2 and 3 b) right on both carbons 3 and 4 c) left at carbon 3 and right at carbon 5 d) more than one correct response e) no correct response

e) no correct response

Which of the following statements concerning the positioning of -OH groups in the Haworth projection for -D-glucose is correct? a) up at carbons 1, 3, and 5 b) down at carbons 2, 3, and 4 c) up at carbons 1 and 3 and down at carbons 2 and 4 d) more than one correct response e) no correct response

A

Which of the following structures is a representation of a cyclic form of D-glucose?

B

Which of the following structures is that of D-glucose?

C

Which of the following structures is that of an L-monosaccharide?

B

Which of the following structures represents a -monosaccharide?

c) lactose

Which of the following substances will produce both glucose and galactose when it is hydrolyzed? a) sucrose b) maltose c) lactose d) amylose

a) enantiomers

Which of the following terms correctly describes the relationship between D-glucose and L-glucose? a) enantiomers b) epimers c) diastereomers d) cis-trans isomers

b) aldopentoses and ketohexoses

Which of the following types of monosaccharides have cyclic forms that involve a 5-membered ring? a) aldopentoses and ketopentoses b) aldopentoses and ketohexoses c) aldohexoses and ketopentoses d) aldohexoses and ketohexoses

a) fructose and ribose

]In which of the following pairs of monosaccharides do the members of the pair contain different numbers of carbon atoms? a) fructose and ribose b) ribose and deoxyribose c) glucose and fructose d) glyceraldehyde and dihydroxyacetone

A Fischer projection is a three-dimensional notation for showing the spatial arrangements of groups of atoms about chiral centers in a molecule. T/F

False

All common disaccharides have beta-one-four linkages. T/F

False

All physical properties of enantiomers are the same. T/F

False

Aspartame, the most used artificial sweetener, is an undigestible trisaccharide. T/F

False

Both cyclic forms of glucose contain a six-membered carbon ring. T/F

False

Diastereomers are stereoisomers whose molecules are mirror images of each other. T/F

False

Enantiomers with more than three carbon atoms must have the same handedness. T/F

False

Fructose, galactose, and ribose are all hexoses. T/F

False

Glucose contain one more -OH group than does galactose. T/F

False

Glucose is both a hexose and a ketose. T/F

False

Lactose intolerance is a genetic condition caused by excessive amounts of the enzyme lactase. T/F

False

Sucrose is a reducing sugar and lactose is a nonreducing sugar. T/F

False

The biochemical basis for different types of blood is a system of polysaccharide markers attached to red blood cell membranes. T/F

False

The molecules glyceraldehyde and dihydroxyketone each contain one chiral center. T/F

False

a) glycogen

In which of the following carbohydrates are two different types of glycosidic linkages present? a) glycogen b) lactose c) amylose d) more than one correct response e) no correct response

a) lactose

In which of the following disaccharides is a (1 ,4) glycosidic linkage present? a) lactose b) sucrose c) maltose d) more than one correct response e) no correct response

c) sucrose and maltose

In which of the following pairs of carbohydrates are both members of the pair disaccharides? a) glucose and fructose b) lactose and amylose c) sucrose and maltose d) cellobiose and cellulose