Deck 11: Carbohydrates: Structure and Function

Question 1

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.

Answer 1

Carbohydrates are used for long term energy storage.

Question 2

In what part of the body does the metabolism of carbohydrates begin?

A) in the mouth
B) in the stomach
C) in the pancreas
D) in the small intestine
E) in the large intestine

Answer 2

in the mouth

Question 3

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

Answer 3

hydroxyl groups and a ketone

Question 4

Which carbon(s) in the Fischer projection below is/are a center of chirality?

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

Question 5

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 6

Which of the following structures is a monosaccharide?

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

Question 7

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 8

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 9

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 10

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 11

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

Question 12

The most common disease in the world is

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

Question 13

Which of the following statements 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 14

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 15

Which of the following foods contain carbohydrates?

A) pineapple
B) tomatoes
C) potatoes
D) wheat
E) All of these foods contain carbohydrates.

Question 16

Which of the following 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.

Question 17

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) Actually, all of these statements are true.

Question 18

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

A) 2
B) 3
C) 4
D) 5
E) 6

Question 19

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

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

Question 20

Which of the following is a monosaccharide?

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

Question 21

Which of the following statements 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 22

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 23

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?

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.

Question 24

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 25

Which of the following structures is an α-anomer?

A)
B)
C)
D)
E)

Question 26

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 27

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 28

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

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

Question 29

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 30

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

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

Question 31

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

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

Question 32

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 33

Which of the following statements best explains how mutarotation occurs in solution?

A) Any C-C can break, opening the ring.
B) The hydroxyl group on the anomeric carbon "floats" between the α and the β position.
C) The hydroxyl group on the anomeric carbon comes off and then reattaches.
D) The bond between the ring oxygen and the anomeric carbon breaks, opening the ring, and then reforms, closing the ring again.
E) All of the above can occur in solution.

Question 34

Which of the following statements 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.
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 center of chirality.

Question 35

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

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

Question 36

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 _________.

A) pyranose; pyranose
B) pyranose; furanose
C) furanose; furanose
D) furanose; pyranose
E) The choices given do not apply to ring forms of sugars.

Question 37

Which of the following species does equilibrium favor in solution?

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

Question 38

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 39

Which one of these molecules is a naturally occurring sugar?

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

Question 40

The figure below illustrates a(n)

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

Question 41

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

Question 42

This disaccharide is composed of two glucose molecules.

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

Question 43

Which of the following glycosidic linkages does the sugar shown below contain?

A) " $\beta$ -(2→4)"
B) " $\alpha$ -(1→4)"
C) " $\beta$ -(1→4)"
D) " $\alpha$ -(2→4)"
E) " $\alpha$ -(2→6)"

Question 44

Cellobiose, shown below, cannot be hydrolyzed into monosaccharides by humans. Which statement best describes why this is the case?

A) Cellobiose contains a $\beta$ -(1→4) glycosidic linkage, which is not a substrate for glycosidases in the human stomach.
B) Human enzymes do not accept glucose molecules as substrates.
C) Cellobiose is composed of monosaccharides that are not part of the human diet.
D) The glycosidic bond in this disaccharide is unusually strong.
E) No disaccharide is hydrolyzed by humans.

Question 45

Which of the following molecules is NOT a polysaccharide?

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

Question 46

Starches in our diet contain _________ of glucose units bonded together.

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

Question 47

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

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

Question 48

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 49

Plants store energy in the form of

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

Question 50

This disaccharide is found in milk.

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

Question 51

A large molecule composed of many repeating units of smaller molecules is called a

A) polymer.
B) monomer.
C) manymer.
D) macromere.
E) carbohydrate.

Question 52

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 53

Which of the following arrows 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 54

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

Question 55

Animals store energy in the form of

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

Question 56

A disaccharide has an $\alpha$ -(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 $\alpha$ 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) All of these statements are true.

Question 57

What type of saccharide is the following molecule?

A) a monosaccharide
B) a disaccharide
C) an oligosaccharide
D) a polysaccharide
E) This molecule is not a sugar.

Question 58

How many monosaccharides are produced when the following sugar is hydrolyzed?

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

Question 59

Which of the following arrows 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 60

Which of the following glycosidic linkages does the sugar shown below contain?

A) " $\beta$ -(2→4)"
B) " $\alpha$ -(1→4)"
C) " $\beta$ -(1→4)"
D) " $\alpha$ -(2→4)"
E) " $\alpha$ -(2→6)"

Question 61

These polysaccharides are made of glucose.

A) amylose
B) amylopectin
C) glycogen
D) cellulose
E) all of the above

Question 62

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?

A) β-glycosidase catalyzes the oxidation of cellulose.
B) β-glycosidase catalyzes the isomerization of β-glycosidic bonds into $\beta$ -glycosidic bonds.
C) β-glycosidase catalyzes the reduction of cellulose.
D) β-glycosidase catalyzes the hydrolysis of cellulose.
E) β-glycosidase catalyzes the dehydration of cellulose.

Question 63

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 64

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 $\beta$ -(1→4) linkage, whereas starch has an $\alpha$ -(1→4) linkage.
E) Starch has a $\beta$ -(1→4) linkage, whereas cellulose has an $\alpha$ -(1→4) linkage.

Question 65

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 66

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 67

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 68

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 69

The result of a patient's Fasting Plasma Glucose Test is 60 mg glucose per deciliter. This patient is

A) normal.
B) hypoglycemic.
C) hyperglycemic.
D) diabetic.
E) both hyperglycemic and diabetic.

Question 70

Insulin acts to __________, whereas glucagon __________.

A) increase blood sugar; decreases blood sugar
B) stimulate gluconeogenesis; stimulates glycogenesis
C) suppress gluconeogenesis; suppresses glycogenesis
D) decrease blood sugar; increases blood sugar
E) stimulate glycogenesis; suppresses glycogenesis

Question 71

Which statement best describes at the molecular level why AB is the universal acceptor?

A) It is the least common blood type.
B) It contains both the type A and type B monosaccharides in addition to the core trisaccharide.
C) It only contains the core trisaccharide and does not have any additional sugars on it.
D) Red blood cells of this type do not have any oligosaccharide markers.
E) Type AB has a completely different oligosaccharide marker than A, B, and O.

Question 72

Which of the following choices matches the descriptions of Type I and Type II diabetes and their treatments?

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

Question 73

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 74

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 75

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 76

Which of the following blood types is most common?

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

Question 77

Which of the following is the best definition for diabetes?

A) Diabetes is hypoglycemia due to an excess of insulin.
B) Diabetes is hypoglycemia due to insulin resistance or insufficient insulin.
C) Diabetes is hyperglycemia due to an excess of insulin.
D) Diabetes is hyperglycemia due to insulin resistance or insufficient insulin.
E) Diabetes is any disorder of blood sugar.

Question 78

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

A) glucose
B) glycogen
C) fructose
D) sucrose
E) All of the above