Question 1

Which of the following amino acids has its isoelectric point at the highest pH?

Accepted Answer

A)   glycine
B)   aspartic acid
C)   valine
D)   arginine
E)   methionineF) A) and B)
G) C) and D)

Question 2

Provide the necessary reagents to convert propionic acid to alanine.

Accepted Answer

The answer of Provide the necessary reagents to convert propionic...

Question 3

Which of the following amino acids has a nonpolar side chain?

Accepted Answer

A)   serine
B)   aspartic acid
C)   asparagine
D)   threonine
E)   leucineF) C) and D)
G) C) and E)

Question 4

Draw the Fischer projection of L-glutamic acid at a pH of 12.

Accepted Answer

The answer of Draw the Fischer projection of L-glutamic acid...

Question 5

Provide the single letter code for the following peptide
Arg-Phe-Tyr-Cys-Asp-Trp-Gln-Ala-Glu-Glu-His-Lys

Accepted Answer

The answer of Provide the single letter code for the...

Question 6

Which amino acid's side chain is negatively charged at biological pH, pH = 7.4?

Accepted Answer

A)   arginine
B)   tyrosine
C)   aspartic acid
D)   serine
E)   glutamineF) C) and D)
G) A) and B)

Question 7

Provide the structure of L-arginine at pH 2.0.

Accepted Answer

The answer of Provide the structure of L-arginine at pH...

Question 8

The reagent used in the determination of the N-terminal amino acid residue of a peptide is ________.

Accepted Answer

A)   carboxypeptidase
B)   phenyl isothiocyanate
C)   dicyclohexylcarbodiimide
D)   ethyl chloroformate
E)   peroxyformic acidF) D) and E)
G) A) and C)

Question 9

________ of a protein usually results in the precipitation of the protein and loss of its biological activity.

Accepted Answer

The answer of ________ of a protein usually results in...

Question 10

Which of the following reagents are commonly used to acylate the amino group of an amino acid?

Accepted Answer

A)   both acetic anhydride and benzyl chloroformate
B)   both benzyl chloroformate and α-bromoacetic acid
C)   both α-bromoacetic acid and tosyl chloride
D)   both tosyl chloride and acetic anhydride
E)   both benzyl chloroformate and tosyl chlorideF) A) and B)
G) C) and D)

Question 11

Which of the following will result in removal of a benzyl ester protecting group?

Accepted Answer

A)   acid hydrolysis only
B)   decarbonylation only
C)   catalytic hydrogenation only
D)   both acid hydrolysis and decarbonylation
E)   both catalytic hydrogenation and acid hydrolysisF) A) and B)
G) A) and C)

Question 12

An amino acid analyzer can be used to determine ________.

Accepted Answer

A)   the sequence of amino acids in a peptide
B)   the identity of the amino acids present in a peptide
C)   the relative amounts of the amino acids present in a peptide
D)   both A and C
E)   both B and CF) B) and C)
G) A) and B)

Question 13

Show where trypsin would cleave the peptide shown below.

Accepted Answer

The answer of Show where trypsin would cleave the peptide...

Question 14

Provide a structure of the tripeptide SGD.

Accepted Answer

The answer of Provide a structure of the tripeptide SGD....

Question 15

Draw the structure of the tetrapeptide Ser-Leu-Phe-Pro.

Accepted Answer

The answer of Draw the structure of the tetrapeptide Ser-Leu-Phe-Pro....

Question 16

Complete hydrolysis of a hexapeptide gives 2 Gly, Leu, Phe, Pro, and Tyr. Reaction of the peptide with phenylisothiocyanate gave the phenylthiohydantoin of Pro. Partial hydrolysis of the peptide gave the following fragments: Phe-Gly-Tyr, Gly-Phe-Gly, Pro-Leu-Gly, Leu-Gly-Phe. What is the structure of the peptide?

Accepted Answer

Pro-Leu-Gl...

Question 17

When a disulfide linkage is formed, the compound containing this new linkage has been ________.

Accepted Answer

A)   oxidized
B)   reduced
C)   electrolyzed
D)   hydrolyzed
E)   dehydratedF) A) and D)
G) A) and C)

Question 18

How can an α-ketoacid be converted to an α-aminoacid?

Accepted Answer

Treat with excess NH...

Question 19

When drawing a peptide, the C-terminus ________.

Accepted Answer

A)   is drawn on the right side
B)   is drawn on the left side
C)   is drawn as -COO-
D)   A and C are both correctE) All of the above
F) B) and C)

Question 20

Draw the dipeptide Val-Tyr.

Accepted Answer

The answer of Draw the dipeptide Val-Tyr....

Exam 24: Amino Acids, Peptides, and Proteins

Which of the following reagents are commonly used to acylate the amino group of an amino acid?

Correct Answer
verified

Provide the single letter code for the following peptide Arg-Phe-Tyr-Cys-Asp-Trp-Gln-Ala-Glu-Glu-His-Lys

Correct Answer
verified

Draw the structure of the tetrapeptide Ser-Leu-Phe-Pro.

Correct Answer
verified

An amino acid analyzer can be used to determine ________.

Correct Answer
verified

When drawing a peptide, the C-terminus ________.

Correct Answer
verified

Draw the dipeptide Val-Tyr.

Correct Answer
verified

Show where trypsin would cleave the peptide shown below.

Correct Answer
verified

Correct Answer
verified
Pro-Leu-Gl...
View Answer

Which amino acid's side chain is negatively charged at biological pH, pH = 7.4?

Correct Answer
verified

Which of the following will result in removal of a benzyl ester protecting group?

Correct Answer
verified

________ of a protein usually results in the precipitation of the protein and loss of its biological activity.

Correct Answer
verified

Which of the following amino acids has a nonpolar side chain?

Correct Answer
verified

Draw the Fischer projection of L-glutamic acid at a pH of 12.

Correct Answer
verified

Provide a structure of the tripeptide SGD.

Correct Answer
verified

Provide the necessary reagents to convert propionic acid to alanine.

Correct Answer
verified

When a disulfide linkage is formed, the compound containing this new linkage has been ________.

Correct Answer
verified

Which of the following amino acids has its isoelectric point at the highest pH?

Correct Answer
verified

The reagent used in the determination of the N-terminal amino acid residue of a peptide is ________.

Correct Answer
verified

Provide the structure of L-arginine at pH 2.0.

Correct Answer
verified

How can an α-ketoacid be converted to an α-aminoacid?

Correct Answer
verified
Treat with excess NH...
View Answer

Exam 24: Amino Acids, Peptides, and Proteins

Which of the following reagents are commonly used to acylate the amino group of an amino acid?

Correct AnswerverifiedShow Answer

Provide the single letter code for the following peptide Arg-Phe-Tyr-Cys-Asp-Trp-Gln-Ala-Glu-Glu-His-Lys

Correct AnswerverifiedShow Answer

Draw the structure of the tetrapeptide Ser-Leu-Phe-Pro.

Correct AnswerverifiedShow Answer

An amino acid analyzer can be used to determine ________.

Correct AnswerverifiedShow Answer

When drawing a peptide, the C-terminus ________.

Correct AnswerverifiedShow Answer

Draw the dipeptide Val-Tyr.

Correct AnswerverifiedShow Answer

Show where trypsin would cleave the peptide shown below.

Correct AnswerverifiedShow Answer

Correct AnswerverifiedPro-Leu-Gl...View AnswerShow Answer

Which amino acid's side chain is negatively charged at biological pH, pH = 7.4?

Correct AnswerverifiedShow Answer

Which of the following will result in removal of a benzyl ester protecting group?

Correct AnswerverifiedShow Answer

________ of a protein usually results in the precipitation of the protein and loss of its biological activity.

Correct AnswerverifiedShow Answer

Which of the following amino acids has a nonpolar side chain?

Correct AnswerverifiedShow Answer

Draw the Fischer projection of L-glutamic acid at a pH of 12.

Correct AnswerverifiedShow Answer

Provide a structure of the tripeptide SGD.

Correct AnswerverifiedShow Answer

Provide the necessary reagents to convert propionic acid to alanine.

Correct AnswerverifiedShow Answer

When a disulfide linkage is formed, the compound containing this new linkage has been ________.

Correct AnswerverifiedShow Answer

Which of the following amino acids has its isoelectric point at the highest pH?

Correct AnswerverifiedShow Answer

The reagent used in the determination of the N-terminal amino acid residue of a peptide is ________.

Correct AnswerverifiedShow Answer

Provide the structure of L-arginine at pH 2.0.

Correct AnswerverifiedShow Answer

How can an α-ketoacid be converted to an α-aminoacid?

Correct AnswerverifiedTreat with excess NH...View AnswerShow Answer

Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
verified
Pro-Leu-Gl...
View Answer

Correct Answer
verified

Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
verified
Treat with excess NH...
View Answer