Question 1

The most widely used method for identifying the N-terminal amino acid in a peptide chain is called the ___.

Accepted Answer

The answer of The most widely used method for identifying...

Question 2

Which of the following amino acids is theoretically capable of existing in diastereomeric forms?

Accepted Answer

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

Question 3

The exact sequence of the different $\alpha$-amino acids along the protein chain is called the ___ of the protein.

Accepted Answer

The answer of The exact sequence of the different $\alpha$-amino...

Question 4

Which of these amino acids is described as an "essential" amino acid?

Accepted Answer

A) Threonine 
B) Glycine 
C) Tyrosine 
D) Serine 
E) All of these are "essential" amino acids. 
A) Threonine 
B) Glycine 
C) Tyrosine 
D) Serine 
E) All of these are "essential" amino acids.

Question 5

Logically,the following "unnatural" amino acid would be substituted for which natural amino acid in the synthesis of peptide analogs?

Accepted Answer

A) Aspartic acid 
B) Glutamine 
C) Lysine 
D) Asparagine 
E) Glutamic acid 
A) Aspartic acid 
B) Glutamine 
C) Lysine 
D) Asparagine 
E) Glutamic acid

Question 6

Which of these natural amino acids contains an -OH group?

Accepted Answer

A) Serine 
B) Threonine 
C) Tyrosine 
D) Two of these. 
E) All of these choices. 
A) Serine 
B) Threonine 
C) Tyrosine 
D) Two of these. 
E) All of these choices.

Question 7

Which of these amino acids is a D amino acid?

Accepted Answer

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

Question 8

What is the enzyme that hydrolyzes glycosidic linkages in the peptidoglycan polymer of gram-positive bacterial cell walls?

Accepted Answer

The answer of What is the enzyme that hydrolyzes glycosidic...

Question 9

Two of the more common ionization techniques for the analysis of biopolymers are:

Accepted Answer

A) "HPLC and MALDI" 
B) "1H-NMR and IR" 
C) "1H-NMR and ESI" 
D) "Peptide sequencer and mass spectrometry" 
E) "ESI and MALDI" 
A) "HPLC and MALDI" 
B) "1H-NMR and IR" 
C) "1H-NMR and ESI" 
D) "Peptide sequencer and mass spectrometry" 
E) "ESI and MALDI"

Question 10

What product would be obtained upon treating alanine with the following reagent?

Accepted Answer

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

Question 11

What is the pI of the following amino acid?

Accepted Answer

A) 2.1 
B) 5.9 
C) 3.2 
D) 6.5 
E) 7.0 
A) 2.1 
B) 5.9 
C) 3.2 
D) 6.5 
E) 7.0

Question 12

Which of these natural amino acids contains a phenolic group?

Accepted Answer

A) Phenylalanine 
B) Tyrosine 
C) Tryptophan 
D) 4-Hydroxyproline 
E) Serine 
A) Phenylalanine 
B) Tyrosine 
C) Tryptophan 
D) 4-Hydroxyproline 
E) Serine

Question 13

A "conjugated protein" is one which:

Accepted Answer

A) possesses catalytic properties. 
B) is a digestive enzyme. 
C) exists largely as an α-helix. 
D) contains unsaturated amino acids. 
E) contains a nonprotein group as part of the molecule. 
A) possesses catalytic properties. 
B) is a digestive enzyme. 
C) exists largely as an α-helix. 
D) contains unsaturated amino acids. 
E) contains a nonprotein group as part of the molecule.

Question 14

Which amino acid would have its isoelectric point near pH 3?

Accepted Answer

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

Question 15

What would be the predominant form of lysine in water at pH 14?

Accepted Answer

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

Question 16

One common method of analysis used to measure the approximate molecular weight of a protein is called ___.

Accepted Answer

The answer of One common method of analysis used to...

Question 17

What is the isoelectric point?

Accepted Answer

It is the pH at which the conc

Question 18

Which of these natural amino acids contains an indole ring?

Accepted Answer

A) Phenylalanine 
B) Tyrosine 
C) Tryptophan 
D) 4-Hydroxyproline 
E) Asparigine 
A) Phenylalanine 
B) Tyrosine 
C) Tryptophan 
D) 4-Hydroxyproline 
E) Asparigine

Question 19

The purple color of the anion formed in the ninhydrin test for α-amino acids is due to:

Accepted Answer

A) the attraction of the anion to a metal in a pi-complex. 
B) intermolecular hydrogen bonding. 
C) molecular vibrations. 
D) the highly conjugated nature of the anion. 
E) the color of the ninhydrin. 
A) the attraction of the anion to a metal in a pi-complex. 
B) intermolecular hydrogen bonding. 
C) molecular vibrations. 
D) the highly conjugated nature of the anion. 
E) the color of the ninhydrin.

Question 20

The 13C NMR spectrum below is for either leucine or isoleucine.
Which of the two amino acids is likely to give this spectrum? Explain.

Accepted Answer

Isoleucine is likely to give this ¹³C NMR

Exam 24: Amino Acids and Proteins

The most widely used method for identifying the N-terminal amino acid in a peptide chain is called the ___.

Which of the following amino acids is theoretically capable of existing in diastereomeric forms?

The exact sequence of the different α\alphaα -amino acids along the protein chain is called the ___ of the protein.

Which of these amino acids is described as an "essential" amino acid?

Logically,the following "unnatural" amino acid would be substituted for which natural amino acid in the synthesis of peptide analogs?

Which of these natural amino acids contains an -OH group?

Which of these amino acids is a D amino acid?

What is the enzyme that hydrolyzes glycosidic linkages in the peptidoglycan polymer of gram-positive bacterial cell walls?

Two of the more common ionization techniques for the analysis of biopolymers are:

What product would be obtained upon treating alanine with the following reagent?

What is the pI of the following amino acid?

Which of these natural amino acids contains a phenolic group?

A "conjugated protein" is one which:

Which amino acid would have its isoelectric point near pH 3?

What would be the predominant form of lysine in water at pH 14?

One common method of analysis used to measure the approximate molecular weight of a protein is called ___.

What is the isoelectric point?

Which of these natural amino acids contains an indole ring?

The purple color of the anion formed in the ninhydrin test for α-amino acids is due to:

The 13C NMR spectrum below is for either leucine or isoleucine. Which of the two amino acids is likely to give this spectrum? Explain.

The Basics

Families of Carbon

Acids and Bases

Nomenclature and Conformations of Alkanes and Cycloalkanes

Stereochemistry

Nucleophilic Reactions

Alkenes and Alkynes I

Alkenes and Alkynes II

Nuclear Magnetic Resonance and Mass Spectrometry

Radical Reactions

Alcohols and Ethers

Alcohols From Carbonyl Compounds

Conjugated Unsaturated Systems

Aromatic Compounds

Reactions of Aromatic Compounds

Aldehydes and Ketones

Carboxylic Acids and Their Derivatives

Reactions at the Α Carbon of Carbonyl Compounds

Condensation and Conjugate Addition Reactions of Carbonyl Compounds

Amines

Transition Metal Complexes

Carbohydrates

Lipids

Nucleic Acids and Protein Synthesis

Filters

The exact sequence of the different $\alpha$ -amino acids along the protein chain is called the ___ of the protein.

The ¹³C NMR spectrum below is for either leucine or isoleucine. Which of the two amino acids is likely to give this spectrum? Explain.