Deck 11: Carbohydrates

Question 1

______is the class of glycoproteins with predominantly N-acetylgalactosamine moieties.

A) Glycosaminoglycans
B) Mucoproteins
C) Starch
D) Lectins
E) Proteoglycans

Answer 1

B

Question 2

What molecule are most sugars attached to prior to their transfer to proteins?

A) GDP
B) GMP
C) AMP
D) UMP
E) UDP

Answer 2

E

Question 3

Which of the following are proteins that bind to specific carbohydrate structures in order to facilitate recognition between proteins and cells?

A) mucoproteins
B) glycosaminoglycans
C) glycoproteins
D) lectins
E) proteoglycans

Answer 3

D

Question 4

In C-type lectins,a _______________ acts as a bridge between the carbohydrate and the protein.

Question 5

_______________ is a disaccharide composed of galactose and glucose joined by a β-1,4 glycosidic bond.

Question 6

In N-linked glycoproteins,the carbohydrate portion is attached to a(n)_____________ residue in the protein.

Question 7

Which of the following terms describes a class of compounds with the molecular formula (CH₂O)_n?

A) proteoglycans
B) glycogen
C) mucoproteins
D) polysaccharides
E) monosaccharides

Question 8

A _______________ is a stereoisomer that is not a mirror image.

Question 9

What type of enzyme synthesizes oligosaccharides?

A) amylase
B) sucrase
C) glycosyltransferase
D) $\beta$ -galactosidase
E) protein kinase

Question 10

Two monosaccharides that differ in stereochemistry at only a single asymmetric carbon are called _____.

A) aldoses
B) epimers
C) anomers
D) pentoses
E) enantiomers

Question 11

A _______________ is a five-membered ring formed from a monosaccharide.

Question 12

When an open-chain aldose cyclizes into a ring,it forms a _______________.

Question 13

A given protein with several potential glycosylation sites can have many different glycosylated structures called ________________.

Question 14

What term describes stereoisomers that are mirror images of each other?

A) anomers
B) epimers
C) enantiomers
D) diastereomers
E) meso compound

Question 15

Which of the following is the storage form of glucose in animals?

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

Question 16

Fehling's solution is used to differentiate between reducing and nonreducing sugars.Which type of ion in Fehling's solution allows for this differentiation?

A) cupric
B) sodium
C) iodide
D) hydroxide
E) bicarbonate

Question 17

Plant starch is composed of amylose,a linear polymer of glucose,and a branched polymer of glucose referred to as _______________.

Question 18

The influenza virus recognizes _______________ (a carbohydrate)residues of glycoproteins present on cell surface.

Question 19

Maltose is composed of two molecules of glucose linked together by a(n)____________ glycosidic bond.

Question 20

Which of the following is among the most abundant organic molecules in the biosphere?

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

Question 21

How is the d or l configuration determined?

Question 22

Draw the structure of lactose.Identify the monosaccharides involved,and identify the type of linkage in lactose.

Question 23

The nutritional storage form(s)of glucose in plants is/are

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

Question 24

At what location(s)within a cell is/are proteins glycosylated?

A) ribosome
B) endoplasmic reticulum
C) Golgi complex
D) lysosome
E) endoplasmic reticulum and Golgi complex

Question 25

Glycoform refers to

A) a single protein type that can have forms that differ only in their glycosylation.
B) glycoproteins from the same gene family.
C) a common core of sugars that can be found on many different proteins.
D) All of the answers are correct.
E) None of the answers is correct.

Question 26

Inhibitors against which viral enzyme have potential as anti-influenza agents?

A) Calnexin
B) Neuraminidase
C) Selectin
D) All of the answers are correct.
E) None of the answers is correct.

Question 27

The simplest carbohydrates are the 3-carbon molecules:

A) d- and l-glyceraldehyde.
B) dihydroxyacetone and d- and l-glyceraldehyde.
C) dihydroxyacetone and glycerate.
D) dihydroxyacetone and glycerol
E) None of the answers is correct.

Question 28

Draw the Haworth projections of the two pyranose forms of d-glucose.

Question 29

Selectins are proteins that

A) selectively bind proteins destined for lysozomes.
B) aid in selection of proteins bound for the Golgi complex.
C) bind immune-system cells as part of the inflammatory response.
D) All of the answers are correct.
E) None of the answers is correct.

Question 30

List some of the reasons why carbohydrates are considered important molecules.

Question 31

Common carbohydrates found in nature are

A) aldehydes with two or more hydroxyl groups.
B) ketones with two or more hydroxyl groups.
C) amines with two or more hydroxyl groups.
D) aldehydes with two or more hydroxyl groups and ketones with two or more hydroxyl groups.
E) All of the answers are correct.

Question 32

What are lectins?

A) proteins that bind the carbohydrates on glycoproteins and other macromolecules
B) proteins that promote cell-cell interaction
C) proteins found in animals, plants, and microorganisms
D) All of the answers are correct.
E) None of the answers is correct.

Question 33

Which of the following explains how some viruses gain entry into specific cells?

A) by attaching to ion channels
B) by cleaving the glycosidic bonds of cell surface glycoproteins and altering protein shapes
C) by binding to glycoproteins on the cell surface that are unique to specific cells
D) All of the answers are correct.
E) None of the answers is correct.

Question 34

What is the difference between an enantiomer and a diastereoisomer? Give examples.

Question 35

Glycoproteins are normally

A) found on membranes.
B) secreted as extracellular proteins.
C) found inside organelles.
D) All of the answers are correct.
E) found on membranes and secreted as extracellular proteins.

Question 36

The enzyme that digests amylopectin is

A) $\alpha$ -amylase.
B) amylopectinase.
C) cellulase.
D) invertase.
E) None of the answers is correct.

Question 37

Fructose can cyclize to (a)

A) pyranose ring.
B) furanose ring.
C) both pyranose and furanose ring forms.
D) All of the answers are correct.
E) None of the answers is correct.

Question 38

Which of the following is the anomer of β-d-glucopyranose?

Question 39

Sugars are commonly linked to which amino acid residues in glycoproteins?

A) tyrosine and asparagine
B) serine, threonine, and asparagine
C) serine, tyrosine, and asparagine
D) serine and glutamine
E) threonine and glutamine

Question 40

An aldehyde and alcohol can react to form a

A) hemialdol.
B) hemiketal.
C) hemiacetal.
D) All of the answers are correct.
E) None of the answers is correct.

Question 41

How does a genetic mutation account for some of the different human blood types?

Question 42

What is the role of l-selectin when produced by an embryo?

Question 43

Describe the mechanism by which N-linked sugars are synthesized and attached to proteins.

Question 44

Compare the structures of amylopectin and amylose.

Question 45

What are the chemical and structural differences between cellulose and glycogen?

Question 46

What is the role of mannose 6-phosphate? What disease is caused by lack of this terminal sugar on glycoproteins?

Question 47

Describe some of the functions of glycosaminoglycans and proteoglycans.

Question 48

Why is it more difficult to determine the structure of the oligosaccharides,when compared to amino acid sequences?

Question 49

What is the advantage of having different blood types within a species?