Discussion 6

Question 1

The simplest of all carbohydrates has ___ carbon atoms.

1

2

3

4

5

6

Answer 1

3

Question 2

Carbohydrates that differ at one stereocenter are called ___________.

anomers

epimers

enantiomers

diastereoisomers

Answer 2

epimers

Question 3

What type of bond links the monomers of a polysaccharide?

peptide bond

glycosidic bond

glucosidic bond

phosphate ester bond

Answer 3

glycosidic bond

Question 4

The disaccharide commonly found in dairy products is ____________

Answer 4

Lactose

Question 5

__________________ is a homopolymer composed of β(1-4)-linked N-acetyl-D-glucosamine residues that is the principle structural component of the exoskeleton of various groups of invertebrates.

Answer 5

Chitin

Question 6

The molecular formula for a monosaccharide is _____.

CnH2n+2On where n>3

CnH2nOn where n≥3

CnH2nOn where n≥4

CnH2n+2On where n>4

none of the above

Answer 6

CnH2nOn where n≥3

Question 7

Glucose and galactose are _____ of each other.

epimers

enantiomers

diastereomers

anomers

none of the above

Answer 7

epimers

Question 8

The _______________ sugars are monosaccharides in which a hydroxyl group is replaced with a hydrogen atom.

Answer 8

deoxy

Question 9

The bonding of alcohols to the anomeric center of a carbohydrate results in the formation of a(n) _____ bond.

anomeric

amide

glycosidic

ester

hydrogen

Answer 9

glycosidic

Question 10

Any sugar that has a free aldehyde group is called a(n) _____.

reducing sugar

nonreducing sugar

ketose

aldohexose

alditol

Answer 10

reducing sugar

Question 11

Which of the following sugars is not a reducing sugar?

glucose

ribose

sucrose

starch

galactose

Answer 11

sucrose

Question 12

Which of the following is the major difference between glycogen and amylopectin?

Glycogen contains α-glycosidic bonds; amylopectin contains β-glycosidic bonds.

Glycogen is branched; amylopectin is linear.

Glycogen contains a reducing end; amylopectin does not.

Glycogen contains about twice the number of branch points as amylopectin.

Glycogen is found in plants; amylopectin is found in animals.

Answer 12

Glycogen contains about twice the number of branch points as amylopectin.

Question 13

Which of the following are characteristic of cellulose?

highly extended chains

β(1→4) glycosidic bonds

extensive hydrogen bonding between individual molecules

unbranched polymer

all of the above

Answer 13

all of the above

Question 14

Unlike proteins and oligonucleotides, polysaccharides _____.

are readily metabolized in the absence of specialized enzymes

often have branched structures

are achiral

are always completely water soluble

are components of every known living organism

Answer 14

often have branched structures

Question 15

Cellulose is _____.

a linear copolymer of glucose and galactose

a branched polymer of glucose

a linear polymer of glucose with β(1→4) linkages

a linear polymer of glucose with α(1→4) linkages

sometimes called starch

Answer 15

a linear polymer of glucose with β(1→4) linkages

Question 16

Sucrose is a ______________ comprised of a molecule of glucose joined to a molecule of fructose through an ________________ glycosidic linkage.

Answer 16

Disacharride, Alpha-1,2-Beta

Question 17

Maltose is a _______________ made of two molecules of glucose joined via an __________________ glycosidic linkage.

Answer 17

Disacharride, Alpha-1,4

Question 18

Lactose is a disaccharide of a molecule of glucose joined to a molecule of_____________ through an ___________________ glycosidic linkage.

Answer 18

Galactose, Beta-1,4

Question 19

A saccharide that has free aldehyde group is called a(n) _____________.

ketose
nonreducing sugar
reducing sugar
aldohexose
alditol

Answer 19

reducing sugar

Question 20

In terms of structure, what is the main difference between α-amylose and cellulose?

Cellulose is linear, but α-amylose is branched.

Cellulose is formed by β-(1->4) glycosidic bonds, but α-amylose is formed by α-(1->4) glycosidic bonds.

Cellulose is branched, but α-amylose is a linear polymer.

Cellulose is a linear polymer of D-glucose, but α-amylose is a linear polymer of D-allose.

Answer 20

Cellulose is formed by β-(1->4) glycosidic bonds, but α-amylose is formed by α-(1->4) glycosidic bonds.