Question 1

Sucrose is hydrolyzed to what two monosaccharides?

Accepted Answer

A)  glucose and fructose 
B)  glucose and galactose 
C)  maltose and fructose 
D)  galactose and lactose 
E)  galactose and maltose 
A)  glucose and fructose 
B)  glucose and galactose 
C)  maltose and fructose 
D)  galactose and lactose 
E)  galactose and maltose

Question 2

An optically active D-aldopentose produced an optically active alditol upon treatment with NaBH4. When this aldopentose was subjected to a Ruff degradation, a D-aldotetrosewas generated. This aldotetrose gave an optically active aldaric acid upon oxidation with HNO3. Use these data to provide the structure of the starting D-aldopentose.

Accepted Answer

Question 3

When preserving foods, sucrose is more commonly used as a sweetener than glucose. Why is this?

Accepted Answer

Sucrose is a nonreducing sugar

Question 4

Provide the Haworth structure of β-D-ribopyranose.

Accepted Answer

The answer of Provide the Haworth structure of β-D-ribopyranose....

Question 5

Show the hydrogen bonding which occurs when guanine and cytosine form a base pair.

Accepted Answer

The answer of Show the hydrogen bonding which occurs when...

Question 6

Which of the following descriptions apply to both D-glucopyranose and L-galactopyranose?
I. They are both ketoses
II. They are both aldoses
III. They are enantiomers of each other
IV. They are diastereomers of each other
V. They are epimers of each other

Accepted Answer

A)  I, III and V 
B)  II and III 
C)  I, IV and V 
D)  II and IV 
E)  II, IV and V 
A)  I, III and V 
B)  II and III 
C)  I, IV and V 
D)  II and IV 
E)  II, IV and V

Question 7

Besides a possible difference in base structure, what is the major structural difference between ribo- and deoxyribonucleosides?

Accepted Answer

Deoxyribonucleosides

Question 8

Would the disaccharide shown below give a positive Tollin's test?

Accepted Answer

The answer of Would the disaccharide shown below give a...

Question 9

Draw the more stable chair conformer of α-D-glucopyranose.

Accepted Answer

The answer of Draw the more stable chair conformer of...

Question 10

In solution, glucose exists as ________.

Accepted Answer

A)  the open-chain form only 
B)  the cyclic hemiacetal form only 
C)  an equilibrium mixture of the open-chain form and cyclic acetal forms 
D)  an equilibrium mixture of the open-chain form and cyclic hemiacetal forms 
A)  the open-chain form only 
B)  the cyclic hemiacetal form only 
C)  an equilibrium mixture of the open-chain form and cyclic acetal forms 
D)  an equilibrium mixture of the open-chain form and cyclic hemiacetal forms

Question 11

The first step of glycolysis is the keto-enol tautomerization of the 6-phosphate ester of D-glucose. Draw the product of this reaction.

Accepted Answer

The answer of The first step of glycolysis is the...

Question 12

Which structure shows the 3 residue segment of DNA with the following sequence: (3' end) GAT (5' end)?

Accepted Answer

A)    
B)    
C)    
D)    
A)    
B)    
C)    
D)

Question 13

What nucleophilic carbon species is used in the Kiliani-Fischer synthesis?

Accepted Answer

The answer of What nucleophilic carbon species is used in...

Question 14

A diastereomer is called erythro if its Fischer projection shows similar groups ________.

Accepted Answer

A)  opposite each other on the same carbon 
B)  equally spaced about a central carbonyl 
C)  directly above and below a central carbonyl 
D)  on the same side of the molecule on adjacent carbons 
E)  on opposite sides of the molecule on adjacent carbons 
A)  opposite each other on the same carbon 
B)  equally spaced about a central carbonyl 
C)  directly above and below a central carbonyl 
D)  on the same side of the molecule on adjacent carbons 
E)  on opposite sides of the molecule on adjacent carbons

Question 15

Fructose forms ________.

Accepted Answer

A)  a five-membered cyclic hemiacetal 
B)  a six-membered cyclic hemiacetal 
C)  a six-membered lactone 
D)  a five-membered lactone 
E)  none of the above 
A)  a five-membered cyclic hemiacetal 
B)  a six-membered cyclic hemiacetal 
C)  a six-membered lactone 
D)  a five-membered lactone 
E)  none of the above

Question 16

Which of the following correctly describes the structural relationship between D-gulose and L-gulose?

Accepted Answer

A)  diastereomers and epimers 
B)  diastereomers but not epimers 
C)  enantiomers 
D)  constitutional isomers 
E)  not isomers 
A)  diastereomers and epimers 
B)  diastereomers but not epimers 
C)  enantiomers 
D)  constitutional isomers 
E)  not isomers

Question 17

Reduction of a 2-ketohexose with NaBH4 yields ________.

Accepted Answer

A)  a single aldohexose 
B)  a mixture of acetals 
C)  a mixture of alditols 
D)  a mixture of cyclic hemiacetals 
E)  a single pyranose 
A)  a single aldohexose 
B)  a mixture of acetals 
C)  a mixture of alditols 
D)  a mixture of cyclic hemiacetals 
E)  a single pyranose

Question 18

Provide the structure of uridine.

Accepted Answer

The answer of Provide the structure of uridine....

Question 19

What D-aldopentose results when D-allose undergoes a Ruff degradation?

Accepted Answer

The answer of What D-aldopentose results when D-allose undergoes a...

Question 20

Which of the following descriptions of the nucleoside uridine does not apply to the structure of the molecule?

Accepted Answer

A)  The uracil base is directly bonded to the 1' position of ribofuranose in the α position. 
B)  The ribofuranose moiety is found in only the D configuration. 
C)  Nitrogen, at position 1 in the uracil base, is directly bonded to the ribofuranose moiety. 
D)  The 5' OH group is replaced with phosphate(s) in the nucleotide structure. 
E)  none of the above 
A)  The uracil base is directly bonded to the 1' position of ribofuranose in the α position. 
B)  The ribofuranose moiety is found in only the D configuration. 
C)  Nitrogen, at position 1 in the uracil base, is directly bonded to the ribofuranose moiety. 
D)  The 5' OH group is replaced with phosphate(s) in the nucleotide structure. 
E)  none of the above

Exam 23: Carbohydrates and Nucleic Acids

Sucrose is hydrolyzed to what two monosaccharides?

When preserving foods, sucrose is more commonly used as a sweetener than glucose. Why is this?

Provide the Haworth structure of β-D-ribopyranose.

Show the hydrogen bonding which occurs when guanine and cytosine form a base pair.

Which of the following descriptions apply to both D-glucopyranose and L-galactopyranose? I. They are both ketoses II. They are both aldoses III. They are enantiomers of each other IV. They are diastereomers of each other V. They are epimers of each other

Besides a possible difference in base structure, what is the major structural difference between ribo- and deoxyribonucleosides?

Would the disaccharide shown below give a positive Tollin's test?

Draw the more stable chair conformer of α-D-glucopyranose.

In solution, glucose exists as ________.

The first step of glycolysis is the keto-enol tautomerization of the 6-phosphate ester of D-glucose. Draw the product of this reaction.

Which structure shows the 3 residue segment of DNA with the following sequence: (3' end) GAT (5' end)?

What nucleophilic carbon species is used in the Kiliani-Fischer synthesis?

A diastereomer is called erythro if its Fischer projection shows similar groups ________.

Fructose forms ________.

Which of the following correctly describes the structural relationship between D-gulose and L-gulose?

Reduction of a 2-ketohexose with NaBH4 yields ________.

Provide the structure of uridine.

What D-aldopentose results when D-allose undergoes a Ruff degradation?

Which of the following descriptions of the nucleoside uridine does not apply to the structure of the molecule?

Structure and Bonding

Acids and Bases; Functional Groups

Structure and Stereochemistry of Alkanes

The Study of Chemical Reactions

Stereochemistry

Alkyl Halides; Nucleophilic Substitution

Structure and Synthesis of Alkenes; Elimination

Reactions of Alkenes

Structure and Synthesis of Alcohols

Reactions of Alcohols

Infrared Spectroscopy and Mass Spectrometry

Nuclear Magnetic Resonance Spectroscopy

Ethers, Epoxides, and Thioethers

Conjugated Systems, Orbital Symmetry, and Ultraviolet Spectroscopy

Aromatic Compounds

Reactions of Aromatic Compounds

Ketones and Aldehydes

Amines

Carboxylic Acids

Carboxylic Acid Derivatives

Condensations and Alpha Substitutions of Carboxyl Compounds

Amino Acids, Peptides, and Proteins

Lipids

Synthetic Polymers

Filters

Reduction of a 2-ketohexose with NaBH₄ yields ________.