Question 1

Why is the s-trans form of an amide bond more stable?

Accepted Answer

A)  There is no s-cis form in an amide bond.
B)  The oxygen is hydrogen-bonded with the nitrogen atom.
C)  The nitrogen is able to be sp2-hybridized.
D)  The more sterically bulky groups are farther apart.E) B) and C)
F) A) and B)

Question 2

What is the major organic product for the following reaction?

Accepted Answer

A)  I
B)  II
C)  III
D)  IVE) B) and C)
F) A) and D)

Question 3

What is the separation of a racemic mixture into its component enantiomers called?

Accepted Answer

A)  Diastereomers
B)  Meso
C)  Resolution
D)  NeutralizationE) C) and D)
F) B) and D)

Question 4

What is the name given to the pH at which the concentration of the zwitterionic form of an amino acid is at a maximum concentration?

Accepted Answer

A)  Electric point
B)  Dipolar point
C)  Neutral point
D)  Isoelectric pointE) A) and B)
F) A) and C)

Question 5

Why do amide bonds exist as reasonably stable s-cis or s-trans isomers at room temperature?

Accepted Answer

A)  These amide bonds are not stable.
B)  There is partial double bond character between the carbonyl carbon and the nitrogen atom.
C)  The oxygen atom is hydrogen-bonded with the nitrogen atom.
D)  The side-chains can form hydrogen bonds.E) B) and D)
F) B) and C)

Question 6

Reaction of a polypeptide,composed of 12 amino acids,with carboxypeptidase A releases Met (C-terminal amino acid) .The polypeptide undergoes partial hydrolysis to give 12 groups of peptides.Use the groups of overlapping amino acids to determine the proper sequence of this polypeptide.Note: Since these lists of peptides are separated by commas,they are not necessarily in the proper sequence. Ser,Lys,Trp-5.Met,Ala,Gly- 9.Lys,Ser
Gly,His,Ala-6.Ser,Lys,Val -10.Glu,His,Val
Glu,Val,Ser-7.Glu,His-11.Trp,Leu,Glu
Leu,Glu,Ser-8.Leu,Lys,Trp-12.Ala,Met

Accepted Answer

A)  Met-Ala-Gly-His-Glu-Val-Ser-Lys-Trp-Leu-Glu-Ser
B)  Met-Ala-Gly-Glu-His-Ser-Val-Lys-Trp-Leu-Glu-Ser
C)  Ser-Glu-Leu-Trp-Lys-Ser-Val-Glu-His-Gly-Ala-Met
D)  Ser-Lys-Leu-Trp-Lys-Ser-Val-His-Glu-Gly-Ala-MetE) A) and D)
F) C) and D)

Exam 27: Amino Acids and Proteins

What is the name given to the pH at which the concentration of the zwitterionic form of an amino acid is at a maximum concentration?

Correct Answer
verified

What is the major organic product for the following reaction?

Correct Answer
verified

Why do amide bonds exist as reasonably stable s-cis or s-trans isomers at room temperature?

Correct Answer
verified

Why is the s-trans form of an amide bond more stable?

Correct Answer
verified

What is the separation of a racemic mixture into its component enantiomers called?

Correct Answer
verified

Correct Answer
verified

Exam 27: Amino Acids and Proteins

What is the name given to the pH at which the concentration of the zwitterionic form of an amino acid is at a maximum concentration?

Correct AnswerverifiedShow Answer

What is the major organic product for the following reaction?

Correct AnswerverifiedShow Answer

Why do amide bonds exist as reasonably stable s-cis or s-trans isomers at room temperature?

Correct AnswerverifiedShow Answer

Why is the s-trans form of an amide bond more stable?

Correct AnswerverifiedShow Answer

What is the separation of a racemic mixture into its component enantiomers called?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
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