Chapter 11  Carbohydrates
Matching Questions
Use the following to answer questions 1-10:
Choose the correct answer from the list below. Not all of the answers will be used.
a) Fehling’s
b) enantiomers
c) UDP
d) glycogen
e) monosaccharides
f) cellulose
g) lectins
h) Heparin
i) axial
j) glycoproteins
k) epimers
l) glycosyltransferases
1 ____________ This class of compounds has the molecular formula of (CH2O)n.
Ans: e
Section:  11.1
2 ____________ These are stereoisomers that are mirror images of each other.
Ans: b
Section:  11.1
3 ____________ These monosaccharides differ at a single asymmetric carbon.
proliferationAns: k
Section:  11.1
4 ____________ This is the most abundant organic molecule in the biosphere.
Ans: f
Section:  11.2
5 ____________ This is a test solution used to identify reducing and nonreducing sugars.
Ans: a
Section:  11.1
6 ____________ The storage form of glucose in animals.
Ans: d
Section:  11.2
7 ____________ This is an example of a glycosaminoglycan.
Ans: h
Section:  11.2
8 ____________ These are the enzymes that synthesize oligosaccharides.
Ans: l
Section:  11.2
9 ____________ Molecule to which most sugars are attached prior to transfer.
Ans: c
Section:  11.2
10 ____________ These proteins bind to specific carbohydrate structures.
Ans: g
Section:  11.3
Fill in the Blank Questions
11 A _______________ is a stereoisomer that is not a mirror image.
Ans:  diastereoisomer    Section:  11.1
12 A _______________ is a five-membered ring formed from a monosaccharide.
Ans:  furanose    Section:  11.1
13 A _______________ is formed when two monosaccharides are linked together via a glycosidic
bond.
Ans:  disaccharide    Section:  11.1
14 Plant starch is composed of amylose, a linear polymer of glucose, and a branched polymer of
glucose referred to as _______________.
Ans:  amylopectin    Section:  11.2
15 Maltose is composed of two molecules of glucose linked together by ____________ glycosidic
bond.
Ans:  α-1,4    Section:  11.2
16 _______________ is a galactose joined to a glucose by a β-1,4 glycosidic bond.
Ans:  Lactose    Section:  11.2
17 In N-linked glycoproteins, the carbohydrate portion is attached to a(n)_____________ residue in
the protein.
Ans:  asparagine    Section:  11.3
18 When the carbohydrate portion is attached to a serine or threonine residue in a glycoprotein, it is
referred to as a(n)_______________ glycoprotein.
Ans:  O-linked    Section:  11.3
19 The influenza virus recognizes _______________ residues of glycoproteins present on cell
surface.
Ans:  sialic acid    Section:  11.4
20 In C-type lectins, a _______________ acts as a bridge between the carbohydrate and the protein.
Ans:  calcium ion    Section:  11.4
Multiple Choice Questions
21 Carbohydrates are
A) polyhydroxy aldehydes.
B) polyhydroxy ketones.
C) polyhydroxy acids.
D) polyhydroxy alcohols.
E)    a and b.
Ans:  E    Section:  Introduction
22 The simplest carbohydrates are
A) D- and L-glyceraldehyde.
B) dihydroxyacetone and D- and L-glyceraldehyde.
C) dihydroxyacetone and glycerate.
D) All of the above.
E) None of the above.
Ans:  B    Section:  11.1
23 An aldehyde and alcohol can react to form a
A) hemiaketal.  D) All of the above.
B) hemiketal.  E) None of the above.
C) hemiacetal.
Ans:  C    Section:  11.1
24 Fructose can cyclize to (a)
A) pyranose ring.
B) furanose ring.
C) both pyranose and furanose ring forms.
D) All of the above.
E) None of the above.
Ans:  C    Section:  11.1
25 The nutritional storage form(s) of glucose in plants.
A) glycogen    B) amylose    C) amylopectin    D) b and c    E) All of the above
Ans:  D    Section:  11.2
26 The enzyme that digests amylopectin.
A)  -amylase  D) All of the above.  B) amylose  E) None of the above.  C) cellulose
Ans:  A    Section:  11.2
27 To which amino acid residues in glycoproteins are the sugars commonly linked?
A) tyrosine and asparagine  D) serine and threonine  B) serine, threonine, and asparagine  E)    a and d  C) serine, tyrosine, and asparagine    Ans:  B    Section:  11.3
28 Glycoproteins are normally
A) found on membranes.
D)    a and b.
B) secreted as extracellular proteins.  E) All of the above.  C) found inside organelles.
Ans:  D    Section:  11.3
29 At what sites in a cell are proteins glycosylated?
A) ribosome  D)    b and c  B) endoplasmic reticulum  E) a, b, and c  C) Golgi complex
Ans:  D    Section:  11.3
30 Which of the following is the anomer of β-D -glucopyranose?
D)
C)
B)
A)
Ans:  C    Section:  11.2
31 Glycoforms refers to
A)    a single protein type that can have forms that vary in 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 above.  E) none of the above.  Ans:  A    Section:  11.3
32 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 above.
E) none of the above.
Ans:  C    Section:  11.4
33 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 above.
E) None of the above.
Ans:  D    Section:  11.4.
34 How do some viruses gain entry into specific cells?
A) by attaching to ion channels
B) by cleaving the glycosidic bonds and altering protein shapes
C) by binding to glycoproteins on the cell surface that are unique to specific cells
D) All of the above.
E) None of the above.
Ans:  C    Section:  11.4
35 Inhibitors against this viral enzyme have potential as anti-influenza agents.
A) calnexin  D) All of the above.
B) neuramidase  E) None of the above.
C) selectin
Ans:  B    Section:  11.4
Short-Answer Questions
36 List some of the reasons carbohydrates are considered important molecules.
Ans: Carbohydrates serve several important functions as fuels, metabolic intermediates, and energy stores. They are the basis of most of the organic matter on our planet. Carbohydrates
serve as the structural framework or building blocks for DNA, RNA, and polysaccharides.
They are also linked to other molecules, such as proteins and lipids, and play important
roles in signaling and structure.
Section:  Introduction

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