Question 1

Which of the following membrane-bound carbohydrates is found in the B antigens of type B blood?

Accepted Answer

A)  N-acetyl-D-galactosamine 
B)  D-galactose 
C)  Both N-acetyl-D-galactosamine and D-galactose 
D)  Neither N-acetyl-D-galactosamine nor D-galactose 
A)  N-acetyl-D-galactosamine 
B)  D-galactose 
C)  Both N-acetyl-D-galactosamine and D-galactose 
D)  Neither N-acetyl-D-galactosamine nor D-galactose

Question 2

Where is a glyosidic linkage found in a disaccharide?

Accepted Answer

A)  between the anomeric carbon atom of the first unit and an -OH group of the second unit 
B)  between an -OH group of the first unit and the anomeric carbon atom of the second unit 
C)  between an -OH group of the first unit and an -OH group of the second unit 
D)  between the anomeric carbon atom of the first unit and the anomeric carbon atom of the second unit 
A)  between the anomeric carbon atom of the first unit and an -OH group of the second unit 
B)  between an -OH group of the first unit and the anomeric carbon atom of the second unit 
C)  between an -OH group of the first unit and an -OH group of the second unit 
D)  between the anomeric carbon atom of the first unit and the anomeric carbon atom of the second unit

Question 3

Identify the linkage between N-acetyl-D-glucosamine and D-glucuronic acid in hyaluronic acid.

Accepted Answer

A)  an α-1,3-glycosidic bond 
B)  an α-1,4-glycosidic bond 
C)  a β-1,3-glycosidic bond 
D)  a β-1,4-glycosidic bond 
A)  an α-1,3-glycosidic bond 
B)  an α-1,4-glycosidic bond 
C)  a β-1,3-glycosidic bond 
D)  a β-1,4-glycosidic bond

Question 4

Examine the given ball-and-stick model. Elements other than hydrogen and carbon are labeled.   Which of the following structures is also a representation of the given model?

Accepted Answer

A)    
B)    
C)    
D)  All of these are correct representations of the given model. 
A)    
B)    
C)    
D)  All of these are correct representations of the given model.

Question 5

Which of the following reactions is involved in the conversion of glucose to gluconate?

Accepted Answer

A)  reduction at carbon 1 
B)  oxidation at carbon 1 
C)  reduction at carbon 6 
D)  oxidation at carbon 6 
A)  reduction at carbon 1 
B)  oxidation at carbon 1 
C)  reduction at carbon 6 
D)  oxidation at carbon 6

Question 6

Identify a D-aldopentose from among the following compounds.

Accepted Answer

A)  D-psicose 
B)  D-fructose 
C)  D-idose 
D)  D-arabinose 
A)  D-psicose 
B)  D-fructose 
C)  D-idose 
D)  D-arabinose

Question 7

Which of the following are the most abundant biological compounds in the plant world?

Accepted Answer

A)  alcohols 
B)  vitamins 
C)  carbohydrates 
D)  proteins 
A)  alcohols 
B)  vitamins 
C)  carbohydrates 
D)  proteins

Question 8

Which of the following statements is true of galactose?

Accepted Answer

A)  It is the most common aldohexose in the human body. 
B)  It is the sweetest naturally occurring carbohydrate. 
C)  It is an important constituent of membranes in the nervous system. 
D)  It is one of the hydrolysis products of the disaccharide sucrose. 
A)  It is the most common aldohexose in the human body. 
B)  It is the sweetest naturally occurring carbohydrate. 
C)  It is an important constituent of membranes in the nervous system. 
D)  It is one of the hydrolysis products of the disaccharide sucrose.

Question 9

Examine the given chemical structures.         Which of the following chemical structures has an L-configuration?

Accepted Answer

A)  A 
B)  B 
C)  C 
D)  D 
E)  None of these has an L-configuration. 
A)  A 
B)  B 
C)  C 
D)  D 
E)  None of these has an L-configuration.

Question 10

Identify a D-2-ketohexose from among the following compounds.

Accepted Answer

A)  D-xylulose 
B)  D-ribulose 
C)  D-erythrulose 
D)  D-psicose 
A)  D-xylulose 
B)  D-ribulose 
C)  D-erythrulose 
D)  D-psicose

Question 11

How many chiral carbons are present in the open-chain form of a ketopentose?

Accepted Answer

A)  one 
B)  two 
C)  three 
D)  four 
A)  one 
B)  two 
C)  three 
D)  four

Question 12

To which class of compounds do glycosides belong?

Accepted Answer

A)  acetals 
B)  hemiacetals 
C)  ethers 
D)  esters 
A)  acetals 
B)  hemiacetals 
C)  ethers 
D)  esters

Question 13

Which carbon atom becomes an anomeric carbon when fructose adopts a furanose structure?

Accepted Answer

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

Question 14

Which carbon atom becomes an anomeric carbon when glucose adopts a pyranose structure?

Accepted Answer

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

Question 15

How many chiral carbons are present in the open-chain form of an aldopentose?

Accepted Answer

A)  two 
B)  three 
C)  four 
D)  five 
A)  two 
B)  three 
C)  four 
D)  five

Question 16

Which of the following statements is true of glucose 6-phosphate?

Accepted Answer

A)  It is a cationic species with a charge of +1. 
B)  It is an electrically neutral molecule. 
C)  It is an anionic species with a charge of −1. 
D)  It is an anionic species with a charge of −2. 
A)  It is a cationic species with a charge of +1. 
B)  It is an electrically neutral molecule. 
C)  It is an anionic species with a charge of −1. 
D)  It is an anionic species with a charge of −2.

Question 17

Which of the following chemical compounds is used as a sweetening agent in "sugarless" gums?

Accepted Answer

A)  xylitol 
B)  gluconic acid 
C)  glucuronic acid 
D)  toluidine 
A)  xylitol 
B)  gluconic acid 
C)  glucuronic acid 
D)  toluidine

Question 18

Which of the following statements is true of the α and β anomers of glucose?

Accepted Answer

A)  Both the α and β anomers of glucose have the same specific rotation. 
B)  Both the α and β anomers of glucose have the same arrangement of -OH groups. 
C)  Both of these statements are correct 
D)  Neither of these statements is correct. 
A)  Both the α and β anomers of glucose have the same specific rotation. 
B)  Both the α and β anomers of glucose have the same arrangement of -OH groups. 
C)  Both of these statements are correct 
D)  Neither of these statements is correct.

Question 19

Why is mutarotation not possible in glycosides?

Accepted Answer

A)  because glycosides do not have an anomeric carbon atom 
B)  because glycosides do not have any stereocenters that show optical activity 
C)  because the acetals in glycosides are not in equilibrium with the open=chain structures 
D)  for none of these reasons 
A)  because glycosides do not have an anomeric carbon atom 
B)  because glycosides do not have any stereocenters that show optical activity 
C)  because the acetals in glycosides are not in equilibrium with the open=chain structures 
D)  for none of these reasons

Question 20

Including their enantiomeric pairs, how many different 2-ketopentoses are present in nature?

Accepted Answer

A)  two 
B)  four 
C)  eight 
D)  sixteen 
A)  two 
B)  four 
C)  eight 
D)  sixteen

Exam 19: Carbohydrates

Which of the following membrane-bound carbohydrates is found in the B antigens of type B blood?

Where is a glyosidic linkage found in a disaccharide?

Identify the linkage between N-acetyl-D-glucosamine and D-glucuronic acid in hyaluronic acid.

Examine the given ball-and-stick model. Elements other than hydrogen and carbon are labeled. Which of the following structures is also a representation of the given model?

Which of the following reactions is involved in the conversion of glucose to gluconate?

Identify a D-aldopentose from among the following compounds.

Which of the following are the most abundant biological compounds in the plant world?

Which of the following statements is true of galactose?

Examine the given chemical structures. Which of the following chemical structures has an L-configuration?

Identify a D-2-ketohexose from among the following compounds.

How many chiral carbons are present in the open-chain form of a ketopentose?

To which class of compounds do glycosides belong?

Which carbon atom becomes an anomeric carbon when fructose adopts a furanose structure?

Which carbon atom becomes an anomeric carbon when glucose adopts a pyranose structure?

How many chiral carbons are present in the open-chain form of an aldopentose?

Which of the following statements is true of glucose 6-phosphate?

Which of the following chemical compounds is used as a sweetening agent in "sugarless" gums?

Which of the following statements is true of the α and β anomers of glucose?

Why is mutarotation not possible in glycosides?

Including their enantiomeric pairs, how many different 2-ketopentoses are present in nature?

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