Deck 13: Carbohydrate Structure and Function

Question 1

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

A) -galactosidase
B) -galactosidase
C) lactase
D) amylase

Answer 1

A

Question 2

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

Answer 2

B

Question 3

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

Answer 3

D

Question 4

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 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

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 8

The image below shows a(n)__________ glycosidic bond.

A) -1,4-
B) -1,4-
C) -1,6-
D) -1,6-

Question 9

Glycoconjugates are linked to proteins or lipids via

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

Question 10

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 11

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 12

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

Question 13

Which glucose homopolymer is generated during daylight hours in plants?

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

Question 14

Which glycan is a major component of plant cell walls?

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

Question 15

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

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

Question 16

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 17

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 18

The image below shows a(n)__________ glycosidic bond.

A) -1,4-
B) -1,4-
C) -1,6-
D) -1,6-

Question 19

Which of the following is classified as a monosaccharide?

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

Question 20

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

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

Question 21

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 22

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 23

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

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

Question 24

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 25

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 26

Amylose can form stable left-handed helical structures because of

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

Question 27

Compared with amylopectin,amylose has __________ glycosidic bonds.

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

Question 28

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 29

Compared with glycogen,amylopectin contains __________ glycosidic bonds.

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

Question 30

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

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

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

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 33

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 34

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 35

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 36

How are glycosaminoglycans attached to proteins?

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

Question 37

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 38

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 39

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

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

Question 40

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

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

Question 41

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 42

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 43

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 44

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 45

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
-lactam ring of penicillin binds to transpeptidase.
C) The
-lactam ring in penicillin is hydrolyzed.
D) The glycine in transpeptidase binds to penicillin.

Question 46

The outer membrane of Gram-negative bacteria contains glycolipids called

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

Question 47

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
-elimination reaction
C) chemical cleavage using a Schiff base intermediate
D) enzymatic cleavage using
-galactosidase

Question 48

What type of inhibitor is penicillin classified as?

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

Question 49

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
-lactamase activity.
C) Penicillin does not bind transpeptidase as well as methicillin.
D) Methicillin does not bind transpeptidase.

Question 50

Which enzyme is produced by penicillin-resistant bacteria?

A) -lactamase
B) peptidase
C) transpeptidase
D) -galactosidase

Question 51

Both methicillin and penicillin are inactive when exposed to

A) transpeptidase.
B) transpeptidase and
-lactamase.
C) -lactamase.
D) variant transpeptidase.

Question 52

Which enzyme does penicillin target in bacteria?

A) -lactamase
B) peptidase
C) transpeptidase
D) -galactosidase

Question 53

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
-elimination reaction
C) chemical cleavage using a Schiff base intermediate
D) enzymatic cleavage using
-galactosidase

Question 54

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

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

Question 55

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 56

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

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

Question 57

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 58

How is penicillin inactivated by penicillin-resistant bacteria?

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

Question 59

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 60

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

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

Question 61

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 62

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 63

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 64

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

Question 65

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 66

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 67

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 68

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 69

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

Question 70

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 71

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 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

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 74

A -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 75

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 76

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 77

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 78

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 79

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

Question 80

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