Deck 13: Carbohydrate Structure and Function

Question 1

Which disaccharide can be found in fermented beverages such as beer?

A) sucrose
B) glucose
C) lactose
D) maltose

Answer 1

maltose

Question 2

The image below shows a(n) glycosidic bond.

A) " $\alpha$ -1,4-"
B) " $\beta$ -1,4-"
C) " $\alpha$ -1,6-"
D) " $\beta$ -1,6-"

Answer 2

" $\beta$ -1,4-"

Question 3

Which simple sugar major group ranges in size from 3 to 20 branched and unbranched sugar residues?

A) monosaccharides
B) disaccharides
C) oligosaccharides
D) polysaccharides

Answer 3

oligosaccharides

Question 4

The following figure shows the cellular processes that synthesize, secrete, and recognize glycoconjugates in eukaryotic cells. Identify the cell surface glycoconjugates.

A) 1
B) 2
C) 5
D) 6

Question 5

The structure of raffinose, stachyose, and verbascose differ in the number of __________ units attached to a _.

A) galactose; lactose
B) glucose; sucrose
C) galactose; sucrose
D) glucose; lactose

Question 6

Eating large amounts of vegetables can cause flatulence because of the presence of

A) glucose.
B) lactose.
C) starch.
D) raffinose.

Question 7

Which glycan is a major component of plant cell walls?

A) cellulose
B) chitin
C) starch
D) glycogen

Question 8

Glycoconjugates are linked to proteins or lipids via

A) London forces.
B) ionic bonds.
C) covalent bonds.
D) hydrogen bonds.

Question 9

The product Beano contains , which helps humans digest raffinose-series oligosaccharides.

A) " $\alpha$ -galactosidase"
B) " $\beta$ -galactosidase"
C) "lactase"
D) "amylase"

Question 10

One of the functions of simple sugars includes

A) enzymatically removing glycans through hydrolysis reactions.
B) functioning as a structural component in invertebrate exoskeletons.
C) acting as metabolic intermediates in energy conversion pathways.
D) enzymatically linking glycans to proteins and lipids.

Question 11

The following figure shows the cellular processes that synthesize, secrete, and recognize glycoconjugates in eukaryotic cells. Identify where lectins are located on the figure.

A) 1
B) 2
C) 5
D) 6

Question 12

Which of the following is classified as a monosaccharide?

A) sucrose
B) glucose
C) lactose
D) maltose

Question 13

The image below shows a(n) glycosidic bond.

A) " $\alpha$ -1,4-"
B) " $\beta$ -1,4-"
C) " $\alpha$ -1,6-"
D) " $\beta$ -1,6-"

Question 14

One of the functions of polysaccharides includes

A) enzymatically removing glycans through hydrolysis reactions.
B) functioning as a structural component in invertebrate exoskeletons.
C) acting as metabolic intermediates in energy conversion pathways.
D) enzymatically linking glycans to proteins and lipids.

Question 15

The growth rate of nonruminating animals often decreases when they eat feed containing __________ because of the inability to digest it.

A) glucose
B) lactose
C) starch
D) raffinose

Question 16

The following figure shows the cellular processes that synthesize, secrete, and recognize glycoconjugates in eukaryotic cells. Identify the cellular structure where glycosyltransferase enzymes function.

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

Question 17

Which of the following oligosaccharides are found in high abundance in some types of vegetables and have been known to cause intestinal distress?

A) lacto-N-tetraose
B) verbascose
C) amylose
D) amylopectin

Question 18

Which glucose homopolymer is generated during daylight hours in plants?

A) sucrose
B) galactose
C) starch
D) glycogen

Question 19

Which glucose homopolymer would be used if a person had to sprint quickly?

A) sucrose
B) galactose
C) starch
D) glycogen

Question 20

Raffinose-series oligosaccharides are hard for humans to digest because

A) humans do not have the enzyme necessary to hydrolyze the glycosidic bonds.
B) they bind to bifidobacteria in the gut.
C) they function as soluble decoys that inhibit pathogenic bacteria from invading the epithelial cells.
D) humans have a large number of competing glycan binding sites.

Question 21

Approximately how many glucose molecules would be present in an amylose polymer with 15 turns of the helix?

A) 60
B) 75
C) 90
D) 105

Question 22

Which glycan contains both $\alpha$ -1,4 glycosidic bonds and $\alpha$ -1,6 glycosidic bonds?

A) amylopectin
B) amylose
C) chitin
D) cellulose

Question 23

What type of antibody or antibodies is/are found in the plasma of a person with type O blood?

A) anti-A
B) anti-B
C) neither anti-A or anti-B
D) both anti-A and anti-B

Question 24

How are glycosaminoglycans attached to proteins?

A) London forces
B) ionic bonds
C) covalent bonds
D) hydrogen bonds

Question 25

Because of antibody recognition, which of the following blood types can donate to a person with type O blood?

A) A
B) B
C) AB
D) O

Question 26

What type of bond is responsible for the rigid nature of the polysaccharide fibril structure?

A) London forces
B) ionic bonds
C) covalent bonds
D) hydrogen bonds

Question 27

Two homozygous parents express the GTA glycosyltransferase. What is the probability of a child with an A blood type?

A) 0%
B) 25%
C) 75%
D) 100%

Question 28

The glycosaminoglycan sulfate is responsible for providing structural support in the cornea of the eye.

A) chondroitin
B) keratan
C) heparan
D) chitin

Question 29

Compared with glycogen, amylopectin contains glycosidic bonds.

A) more $\alpha$ -1,6
B) fewer $\alpha$ -1,6
C) only $\alpha$ -1,4
D) only $\alpha$ -1,6

Question 30

Amylose can form stable left-handed helical structures because of

A) London forces.
B) ionic bonds.
C) covalent bonds.
D) hydrogen bonds.

Question 31

A person who only expresses the GTA enzyme and not the GTB enzyme will have which blood type?

A) O
B) A
C) B
D) AB

Question 32

Compared with amylopectin, amylose has glycosidic bonds.

A) more $\alpha$ -1,6
B) fewer $\alpha$ -1,6
C) only $\alpha$ -1,4
D) only $\alpha$ -1,6

Question 33

What type of antigen(s) is/are expressed on the red blood cell of a personal with type A blood?

A) antigen A
B) antigen B
C) both antigen A and antigen B
D) neither antigen A or antigen B

Question 34

If one homozygous parent expresses the GTA glycosyltransferase and the other homozygous parent expresses the GTP glycosyltransferase, what is the probability of a child with a blood type of O?

A) 0%
B) 25%
C) 75%
D) 100%

Question 35

What would the predicted enzymatic product be when cellulose is exposed to cellulase?

A) pectin
B) hemicellulose
C) cellotetraose
D) glucose

Question 36

What is the blood type of a person who fails to express either the GTA or GTB glycosyltransferases?

A) O
B) A
C) B
D) AB

Question 37

What type of antibody or antibodies is/are found in the plasma of a person with type AB blood?

A) anti-A
B) anti-B
C) neither anti-A or anti-B
D) both anti-A and anti-B

Question 38

The glycan group on glycoproteins and glycolipids on the red blood cells all contain the glycan subgroup(s)

A) O.
B) Gal.
C) GalNAc.
D) Gal and GalNAc.

Question 39

A person who only expresses the GTB enzyme and not the GTA enzyme will have which blood type?

A) O
B) A
C) B
D) AB

Question 40

Which glycan contains a covalently linked dimeric protein that functions as a protein anchor?

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

Question 41

Compared with Gram-negative bacteria, Gram-positive bacteria have a

A) thicker peptidoglycan layer.
B) thinner peptidoglycan layer.
C) thinner outer membrane.
D) thicker outer membrane.

Question 42

What method is used to release the O-linked glycan groups from the membrane-associated glycoconjugates shown in 2 in the figure below?

A) enzymatic cleavage using PNGaseF
B) chemical cleavage using a $\beta$ -elimination reaction
C) chemical cleavage using a Schiff base intermediate
D) enzymatic cleavage using $\beta$ -galactosidase

Question 43

What type of antibody or antibodies is/are found in the plasma of a person with type A blood?

A) anti-A
B) anti-B
C) neither anti-A or anti-B
D) both anti-A and anti-B

Question 44

Crystal violet stains Gram-positive bacteria because Gram-positive bacteria have a(n)

A) outer membrane layer that collapses, trapping the crystal violet molecules.
B) thinner peptidoglycan layer that allows the crystal violet molecules to pass through the pores.
C) thinner peptidoglycan layer that collapses, trapping the crystal violet molecules.
D) thicker peptidoglycan layer that collapses, trapping the crystal violet molecules.

Question 45

Both methicillin and penicillin are inactive when exposed to

A) "transpeptidase."
B) "transpeptidase and $\beta$ -lactamase."
C) " $\beta$ -lactamase."
D) "variant transpeptidase."

Question 46

Penicillin kills bacteria by inhibiting the biosynthesis of the cell wall. How does penicillin cause the inhibition?

A) The transpeptidase of the bacteria binds to methicillin.
B) The carbonyl carbon of the $\beta$ -lactam ring of penicillin binds to transpeptidase.
C) The $\beta$ -lactam ring in penicillin is hydrolyzed.
D) The glycine in transpeptidase binds to penicillin.

Question 47

Which enzyme is produced by penicillin-resistant bacteria?

A) " $\beta$ -lactamase"
B) "peptidase"
C) "transpeptidase"
D) " $\alpha$ -galactosidase"

Question 48

What is the first step when analyzing glycan groups on a glycoprotein?

A) The glycan groups must undergo liquid chromatography to separate the different components of the mixture.
B) Mass spectrometry should be used to identify the glycans based on their mass to charge ratio.
C) The glycan groups must be separated from the protein moiety using a cleavage reaction.
D) The glycan groups must undergo column chromatography to separate the glycan groups from the lipid moiety.

Question 49

What type of antibody or antibodies is/are found in the plasma of a person with type B blood?

A) anti-A
B) anti-B
C) neither anti-A or anti-B
D) both anti-A and anti-B

Question 50

Gram-negative bacteria resist staining with crystal violet because Gram-negative bacteria have a(n)

A) outer membrane layer that collapses, releasing the crystal violet molecules.
B) thinner peptidoglycan layer that does not retain the crystal violet molecules.
C) thinner peptidoglycan layer that collapses, releasing the crystal violet molecules.
D) thicker peptidoglycan layer that collapses, releasing the crystal violet molecules.

Question 51

Which functional group on penicillin forms a complex with transpeptidase of the bacterial wall?

A) sulfide
B) amine
C) hydroxyl
D) carbonyl

Question 52

Gram-positive bacteria have a peptidoglycan layer that consists of , which provides structural support and influences the uptake of charged biomolecules.

A) starch
B) lipopolysaccharides
C) lipoteichoic acid
D) hyaluronic acid

Question 53

How is penicillin inactivated by penicillin-resistant bacteria?

A) Transpeptidase binds to methicillin.
B) The carbonyl carbon of the $\beta$ -lactam ring binds to transpeptidase.
C) The $\beta$ -lactam ring in penicillin is hydrolyzed.
D) The serine in transpeptidase binds to penicillin.

Question 54

What method is used to release the N-linked glycan groups from the membrane-associated glycoconjugates shown in 1 in the figure below?

A) enzymatic cleavage using PNGaseF
B) chemical cleavage using a $\beta$ -elimination reaction
C) chemical cleavage using a Schiff base intermediate
D) enzymatic cleavage using $\beta$ -galactosidase

Question 55

What type of inhibitor is penicillin classified as?

A) reversible
B) competitive
C) suicide
D) uncompetitive

Question 56

The outer membrane of Gram-negative bacteria contains glycolipids called

A) cellulose.
B) lipopolysaccharides.
C) lipoteichoic acid.
D) hyaluronic acid.

Question 57

Gram-negative bacteria contain which potent inflammatory agent in animals?

A) cellulose
B) lipopolysaccharide
C) lipoteichoic acid
D) hyaluronic acid

Question 58

Which amino acid does penicillin form a complex with on transpeptidase?

A) aspartic acid
B) lysine
C) alanine
D) serine

Question 59

Which enzyme does penicillin target in bacteria?

A) " $\beta$ -lactamase"
B) "peptidase"
C) "transpeptidase"
D) " $\alpha$ -galactosidase"

Question 60

What is an advantage of using methicillin compared with penicillin?

A) Penicillin is susceptible to inactivation by mutant transpeptidase enzymes.
B) Methicillin is resistant to $\beta$ -lactamase activity.
C) Penicillin does not bind transpeptidase as well as methicillin.
D) Methicillin does not bind transpeptidase.

Question 61

Glycan arrays can be coupled with to qualitatively compare fractionated cell extracts from different sources.

A) MALDI-TOF
B) HPLC
C) size exclusion chromatography
D) mass spectrometry

Question 62

A $\beta$ -elimination reaction is used in glycan characterization to

A) label the antibody arrays.
B) fluorescently label glycoproteins.
C) cleave the O-linked glycans.
D) cleave the N-linked glycans.

Question 63

The figure below is a fluorescence readout from a lectin array. What can be deduced from B?

A) There is no interaction between the glycan and the lectin in the well.
B) There is a glycan-lectin interaction in the well.
C) There is an interaction, but there is no way to determine the species that are interacting.
D) Glycan cleavage from the glycoconjugate has been achieved.

Question 64

Which technique provides information about the arrangement of sugars in a glycan fraction?

A) glycan arrays
B) MALDI-TOF
C) mass spectrometry
D) high-performance liquid chromatography

Question 65

The glycan fragment shown on the right has been cleaved by glycosylase enzymes, and HPLC analysis has produced the peaks 1 to 6. Which of the following fragments corresponds to peak 5?

A)

B)
C)
D)

Question 66

The glycan fragment shown below on the right has been cleaved by glycosylase enzymes and HPLC analysis has produced the peaks 1 to 6. Which of the following fragments corresponds to peak 1?

A)
B)
C)
D)

Question 67

Arrays made with chemically synthesized glycans are used to investigate glycan-binding properties

A) of different arrangements of sugar groups using HPLC.
B) by comparing the mass-to-charge ratio of the fragments with known glycan groups.
C) of different types of pathogenic bacteria using HPLC.
D) by comparing the affinity of lectins with structurally related glycan groups.

Question 68

Which fluorescent dye is used to label glycans before HPLC?

A) 2-aminobenzamide
B) sodium hydroxide and sodium borohydride
C) sodium cyanoborohydride
D) PNGaseF

Question 69

To detect lectins on the surface of pathogenic and nonpathogenic bacteria, __________ would be used.

A) HPLC
B) MALDI-TOF
C) a glycan array
D) column chromatography

Question 70

The glycan fragment shown below on the right has been cleaved by glycosylase enzymes, and HPLC analysis has produced the peaks 1 to 6. Which of the following fragments corresponds to peak 6?

A)
B)
C)
D)

Question 71

Which technique can identify N-linked glycans in a mixed sample?

A) lectin arrays
B) glycan arrays
C) mass spectrometry
D) high-performance liquid chromatography

Question 72

One common way to characterize glycans is to

A) digest the glycan into fragments using trypsin and chymotrypsin.
B) use affinity chromatography to recognize the different sugars.
C) incubate fluorescently labeled glycoproteins with lectin.
D) use ELISA to determine the structure.

Question 73

Why are glycans more difficult to structurally analyze compared with proteins or nucleic acids?

A) Proteins are smaller than most glycans.
B) Nucleic acids are polar, whereas most glycans are nonpolar.
C) Sugar synthesis is a template-directed process.
D) Glycans have sugar isomers with identical masses.

Question 74

In a lectin array, how are lectin proteins attached to the solid support?

A) van der Waals interactions
B) hydrogen bonding
C) covalent bonding
D) ionic interactions

Question 75

Explain the difference between simple sugars, polysaccharides, and glycoconjugates.

Question 76

The figure below is a fluorescence readout from a lectin array. What can be deduced from A?

A) There is no interaction between the glycan and the lectin in the well.
B) There is a glycan-lectin interaction in the well.
C) There is an interaction, but there is no way to determine the species that are interacting.
D) Glycan cleavage from the glycoconjugate has been achieved.

Question 77

Explain the connection the disaccharide lactose has to lacto-N-tetraose and lacto-N-fucopentaose I that is found in human breast milk.

Question 78

Give an example of a mono-, di-, and polysaccharide and explain the biological importance of each.

Question 79

Approximately 11 different monosaccharides are used as building blocks of glycan groups in glycoconjugates. However, a predictive sugar code has been difficult to identify. Propose three reasons for this difficulty.

Question 80

Explain how sucrose is related to raffinose, stachyose, and verbascose.