Deck 14: Carbohydrates: Structure and Function

Question 1

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

A) Naturally occurring sugars do not have multiple hydroxyl groups on a single carbon.
B) D-sugars are much more common than L-sugars.
C) Naturally occurring sugars are polyhydroxylated.
D) Naturally occurring sugars contain a carbonyl.
E) All of the above are true statements.

Answer 1

All of the above are true statements.

Question 2

Which statement BEST describes how brushing your teeth prevents cavities?

A) Toothpaste stops the metabolism of glucose.
B) Toothpaste neutralizes lactic acid.
C) Brushing removes sugars.
D) Brushing removes anaerobic bacteria.
E) Toothpaste increases pH in the mouth.

Answer 2

Brushing removes sugars.

Question 3

What is produced by cellular respiration?

A) oxygen
B) sugars
C) carbon dioxide, water, and energy
D) oxygen and energy
E) oxygen, sugars, and energy

Answer 3

carbon dioxide, water, and energy

Question 4

Which glycosidic linkage does the sugar shown below contain?

A) β-(2→4)
B) α-(1→4)
C) β-(1→4)
D) α-(2→4)
E) α-(2→6)

Question 5

Below is the open-chain form of fructose, followed by several cyclic monosaccharides.Choose the cyclic monosaccharides that are the ring form of fructose.

A) Only structure II is D-fructose.
B) Only structure III is D-fructose.
C) Both structures I and II are D-fructose.
D) Both structure III and IV are D-fructose.
E) All of these structures are D-fructose.

Question 6

Photosynthesis and cellular respiration together form___________.

A) metabolism
B) catabolism and anabolism
C) energy and matter
D) a biochemical pathway
E) the carbon cycle

Question 7

Which of the following features is NOT shared by all monosaccharides?

A) Monosaccharides cannot be hydrolyzed into simpler carbohydrates.
B) Monosaccharides all contain six carbons.
C) Monosaccharides have an aldehyde or a ketone.
D) Monosaccharides contain two or more alcohols.
E) Monosaccharides are polyhydroxylated.

Question 8

Type _____ blood is the universal donor, whereas type _____ is the universal recipient.

A) O; AB
B) AB; O
C) A; B
D) B; A
E) O; A or B

Question 9

Which of the following statements related to the formation of dental caries is FALSE?

A) Anaerobic bacteria produce lactic acid.
B) Anaerobic bacteria convert glucose into carbon dioxide and water.
C) Lactic acid reduces the pH of the environment of the tooth enamel to pH 4-5.
D) Tooth enamel dissolves in a pH 4-5 environment.
E) Brushing removes sugars from the teeth.

Question 10

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

A) an aldehyde only
B) hydroxyl groups only
C) hydroxyl groups and an alkene
D) hydroxyl groups and a ketone
E) hydroxyl groups and an aldehyde

Question 11

Which of the following types of carbohydrates can be hydrolyzed to give smaller molecules? I.Monosaccharides
II)Disaccharides
III)Oligosaccharides
IV)Polysaccharides

A) I only
B) II and IV only
C) III only
D) I and II only
E) II, III, and IV

Question 12

Do you expect monosaccharides to be soluble in water?

A) Yes, because monosaccharides are acidic.
B) No, because monosaccharides have too many carbons to be soluble.
C) Yes, because monosaccharides can hydrogen bond with water.
D) No, because monosaccharides cannot form intermolecular attractive forces with water.
E) Yes, because monosaccharides are basic.

Question 13

Sucrose, the disaccharide shown below, is a nonreducing sugar because

A) it is a disaccharide.
B) ring A can open and form a carbonyl.
C) ring B can open and form a carbonyl.
D) it contains a glycosidic linkage.
E) neither ring can open.

Question 14

Which object is chiral?

A) a screw
B) a nail
C) a pencil
D) a table
E) a bed

Question 15

A racemic mixture is

A) a 50:50 mixture of enantiomers.
B) optically active.
C) a pure sample of a single enantiomer.
D) dextrorotatory.
E) indicated by the IUPAC prefix R.

Question 16

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

A) structure a
B) structure b
C) structure c
D) structure d
E) structure e

Question 17

What is the relationship between D- and L-glucose?

A) They are identical.
B) They are constitutional isomers.
C) They are diastereomers.
D) They are enantiomers.
E) They are conformers.

Question 18

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

A)
B)
C)
D)
E)

Question 19

Which disaccharide is found in milk?

A) lactose
B) sucrose
C) cellobiose
D) maltose
E) both cellobiose and maltose

Question 20

Nature produces predominantly __________-carbohydrates and _______-amino acids.

A) D, D
B) D, L
C) L, D
D) L, L
E) Nature does not favor one stereoisomer over another.

Question 21

What is the relationship between the two molecules shown?

A) identical molecules
B) isomers
C) enantiomers
D) conformations
E) diastereomers

Question 22

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.

A) ketone and pyranose
B) aldehyde and pyranose
C) carboxylic acid and furanose
D) carboxylic acid and pyranose
E) aldehyde and furanose

Question 23

Animals cannot digest________, but ruminants such as horses and cows have bacteria in their digestive track that can digest it.

A) amylose
B) amylopectin
C) glycogen
D) cellulose
E) amylose and amylopectin

Question 24

Select the species present in higher concentration at equilibrium in aqueous solution.

A) I
B) II
C) III
D) II and III
E) There are equal concentrations of these three species in solution.

Question 25

How are disaccharides separated into two monosaccharides?

A) It is not possible to separate disaccharides into monosaccharides.
B) by esterification
C) by hydration
D) by hydrolysis
E) by amidation

Question 26

What do the IUPAC prefixes R and S indicate about a molecule?

A) the relative size of the molecule
B) the solubility of the molecule
C) whether the molecule is a sugar or not
D) the configuration of chirality center
E) the reactivity of the molecule

Question 27

Which one of these molecules is a naturally occurring sugar?

A)
B)
C)
D)
E)

Question 28

A patient with chronic pancreatitis has her pancreas removed.Which of the following effects would be most likely?

A) nothing
B) the regeneration of the pancreas
C) type I diabetes
D) type II diabetes
E) hypoglycemia

Question 29

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

A) structure a
B) structure b
C) structure c
D) structure d
E) structure e

Question 30

How are glycosidic linkages broken during catabolism of sugars?

A) by oxidation
B) by reduction
C) by hydrolysis
D) by hydrogenation
E) by dehydration

Question 31

The structures of mannose and galactose are given below.What is the relationship between these two monosaccharides?

A) They are identical.
B) They are constitutional isomers.
C) They are diastereomers.
D) They are enantiomers.
E) They are conformers.

Question 32

The most common polysaccharides found in plants and animals are polymers of

A) galactose.
B) glucose.
C) fructose.
D) glucose and fructose.
E) glucose, fructose, and galactose.

Question 33

The following molecule is a __________.

A) ketotriose
B) ketohexose
C) aldopentose
D) ketotetrose
E) aldohexose

Question 34

Which of the following classes of biomolecules causes dental caries?

A) carbohydrates
B) proteins
C) fats
D) nucleic acids
E) All foods cause dental caries.

Question 35

Which of the following sugars is called "blood sugar"?

A) glucose
B) glycogen
C) fructose
D) sucrose
E) All of the above are called blood sugar.

Question 36

Which statement BEST describes mutarotation?

A) The open chain, α-anomer and β-anomer of a sugar are in equilibrium in solution.
B) The sugar spins around (rotates)in solution.
C) The sugar mutates in solution.
D) The sugar decomposes in solution.
E) The sugar both spins around and mutates in solution.

Question 37

Which statement BEST describes photosynthesis?

A) the breakdown of starch into CO₂, H₂O, and energy
B) the breakdown of starch into CO₂ and H₂O using energy
C) the synthesis of starch from CO₂, H₂O, and energy
D) the synthesis of starch and energy from CO₂ and H₂O
E) Photosynthesis applies to all of the above processes.

Question 38

The Fischer projection for fructose is shown below.Which carbon determines whether the sugar is D- or L-?

A) carbon A
B) carbon B
C) carbon C
D) carbon D
E) carbon E

Question 39

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?

A) Nothing, blood type does not matter in organ transplants.
B) Nothing, type O is the universal recipient.
C) organ failure
D) coma
E) a mild allergic reaction

Question 40

In which of the sugars below is the arrow pointing to the carbon that determines whether a sugar is α- or β-?

A) structure a
B) structure b
C) structure c
D) structure d
E) structure e

Question 41

Why can't insulin be taken orally?

A) It does not taste very good.
B) Enzymes in the saliva break it down.
C) Hydrolysis of insulin occurs in the stomach.
D) It is not possible to store insulin.
E) All of the above

Question 42

Molecules that have a different configuration at one or more chirality centers, but not all chirality centers, are called __________.

A) identical molecules
B) isomers
C) enantiomers
D) conformations
E) diastereomers

Question 43

Which of the following blood types can be donated to someone with type A blood?

A) type A only
B) type A or type O
C) type A or type AB
D) any of the blood types except A
E) Type A can receive blood from any of the blood types.

Question 44

The figure below illustrates a(n)

A) monosaccharide.
B) simple sugar.
C) disaccharide.
D) polysaccharide.
E) oligosaccharide.

Question 45

Starches in our diet can contain up to __________of glucose units.

A) tens
B) hundreds
C) thousands
D) millions
E) billions

Question 46

Which of the following sugars is the enantiomer of D-glucose?

A) sugar a
B) sugar b
C) sugar c
D) sugar d
E) sugar e

Question 47

Which of the following blood types is MOST common?

A) A
B) B
C) AB
D) O
E) They are equally common.

Question 48

Plants store energy in the form of

A) amylose.
B) amylopectin.
C) glycogen.
D) cellulose.
E) amylose and amylopectin.

Question 49

Which arrow is pointing to a glycosidic bond?

A) a only
B) b only
C) c only
D) b and c
E) b, c, and d

Question 50

What is the relationship between the two molecules shown?

A) identical molecules
B) isomers
C) enantiomers
D) conformations
E) diastereomers

Question 51

What polysaccharides are made of glucose?

A) amylose
B) amylopectin
C) glycogen
D) cellulose
E) All of the above are made of glucose.

Question 52

Which statement BEST describes how a cell distinguishes between a host cell and foreign cell?

A) Antibodies detect foreign cells.
B) This is what T-cells do.
C) Oligosaccharide cell markers on the surface of the cell do this.
D) A cell sends out special proteins to do this.
E) The proteins within the cell membrane do this.

Question 53

Which glycosidic linkage does the sugar shown below contain?

A) β-(2→4)
B) α-(1→4)
C) β-(1→4)
D) α-(2→4)
E) α-(2→6)

Question 54

What is the relationship between the following two molecules?

A) They are enantiomers.
B) They are identical.
C) They are conformers.
D) They are constitutional isomers.
E) They are unrelated.

Question 55

Which of the following is NOT a function of carbohydrates?

A) Carbohydrates are used for long-term energy storage.
B) Carbohydrates are fuels for cells.
C) Carbohydrates are part of DNA and RNA.
D) Carbohydrates are used in cellular recognition.
E) Carbohydrates make some foods taste sweet.

Question 56

Which statement about enantiomers is TRUE?

A) Enantiomers have different boiling points and melting points.
B) Enantiomers are easy to separate in the laboratory.
C) Enantiomers bind to receptors equally effectively.
D) Only one enantiomer of a drug will have a pharmacological effect.
E) Enantiomers may have different properties in a chiral environment.

Question 57

Which arrow is pointing to a glycosidic bond?

A) a only
B) b only
C) c only
D) b and c
E) b, c, and d

Question 58

Which statement does NOT describe the anomeric carbon?

A) It is the carbon of the carbonyl in the open-chain form of the sugar.
B) This carbon is attached to two oxygens in the ring form of the compound.
C) The hydroxyl group on this carbon can be above or below the ring.
D) Glucose does not contain an anomeric carbon.
E) The anomeric carbon is a chirality center.

Question 59

Which statement about chiral molecules is FALSE?

A) Monosaccharides D-glyceraldehyde and L-glyceraldehyde are enantiomers.
B) Chiral molecules are nonsuperimposable on their mirror image.
C) D-glyceraldehyde and L-glyceraldehyde can be synthesized in the laboratory.
D) Chiral molecules are extremely rare in the body.
E) D-glyceraldehyde, but not L-glyceraldehyde, is produced by our cells.

Question 60

The most common disease in the world is

A) heart disease.
B) cancer.
C) tooth decay.
D) amoebic dysentery.
E) malaria.

Question 61

How many stereogenic centers does the following molecule have?

A) 0
B) 1
C) 2
D) 3
E) 4

Question 62

The Fischer projection for fructose is shown below.Is it a D-sugar or an L-sugar?

A) It is a D-sugar because the hydroxyl at carbon A is to the right.
B) It is a D-sugar because the carbonyl at carbon B is to the right.
C) It is a D-sugar because the hydroxyl at carbon C is to the right.
D) It is an L-sugar because the carbonyl at carbon B is to the right.
E) It is an L-sugar because the hydroxyl at carbon C is to the right.

Question 63

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

A) all carbons
B) carbon I only
C) carbon I and VI only
D) carbons II, III, IV, and V
E) carbons II through VI

Question 64

Which structures is an α-anomer?

A) structure a
B) structure b
C) structure c
D) structure d
E) structure e

Question 65

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?

A) Cellulose is composed of D-glucose, whereas starch is composed of L-glucose.
B) Cellulose and starch are connected together on different carbons.
C) Cellulose is composed of L-glucose, whereas starch is composed of D-glucose.
D) Cellulose has a β-(1→4)linkage, whereas starch has an α-(1→4)linkage.
E) Starch has a β-(1→4)linkage, whereas cellulose has an α-(1→4)linkage.

Question 66

A molecule that is chiral has no _________.

A) tetrahedral carbons
B) heteroatoms
C) mirror plane
D) reflection
E) conformations

Question 67

The Fischer projection for fructose is shown below.Fructose is a _________.

A) triose
B) tetrose
C) pentose
D) hexose
E) heptose

Question 68

How can it be determined whether a sugar is α- or β- by looking at the Haworth projection?

A) α-anomer: The -OH on the anomeric carbon is above the ring.β-anomer: The -OH on the anomeric carbon is below the ring.
B) α-anomer: The -CH₂OH of carbon 6 is above the ring.β-anomer: The -CH₂OH of carbon 6 is below the ring.
C) α-anomer: The -OH on the anomeric carbon is below the ring.β-anomer: The -OH on the anomeric carbon is above the ring.
D) α-anomer: The -CH₂OH of carbon 6 is below the ring.β-anomer: The -CH₂OH of carbon 6 is above the ring.
E) Both b and d are true.

Question 69

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

A) choice a
B) choice b
C) choice c
D) choice d
E) choice e

Question 70

A molecule that is nonsuperimposable on its mirror image is/are ________.

A) impossible
B) chiral
C) reflective
D) identical
E) conformers

Question 71

Animals store energy in the form of

A) amylose.
B) amylopectin.
C) glycogen.
D) cellulose.
E) amylose and amylopectin.

Question 72

D-glucose is shown below.Which of the choices below is L-glucose?

A) sugar a
B) sugar b
C) sugar c
D) sugar d
E) sugar e

Question 73

Which of the following is a monosaccharide?

A) cellulose
B) starch
C) glucose
D) sucrose
E) maltose

Question 74

A disaccharide has an α-(1→4)glycosidic linkage.Which statement about this sugar is TRUE?

A) Both monosaccharides in the disaccharide are linked at their anomeric carbon.
B) Both monosaccharides in the disaccharide are the α-anomer.
C) No part of the disaccharide can undergo mutarotation.
D) The closed ring form of the sugar linked at its carbon-4 is in equilibrium with its open-chain form.
E) It is a nonreducing sugar.

Question 75

Which carbon determines whether the sugar below is D- or L-?

A) carbon A
B) carbon B
C) carbon C
D) carbon D
E) carbon E

Question 76

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

A) choice a
B) choice b
C) choice c
D) choice d
E) choice e

Question 77

Which carbon of L-dopa is a chirality center?

A) carbon A
B) carbon B
C) carbon C
D) carbon D
E) carbon E

Question 78

Which of the following molecules is NOT a polysaccharide?

A) amylose
B) amylopectin
C) cellulose
D) glycogen
E) glucose

Question 79

Which of the following statements describes the role of insulin in the body? I.Insulin signals to cells to allow glucose to enter.
II)Insulin stimulates the conversion of glucose to glycogen.
III)Insulin stimulates the hydrolysis of glucose from glycogen.

A) All of these describe the role of insulin in the body.
B) I only
C) II only
D) III only
E) I and II

Question 80

What is the relationship between the two molecules below?

A) They are enantiomers.
B) They are identical.
C) They are conformers.
D) They are constitutional isomers.
E) They are unrelated.