Question 1

Which of the following is the correct sequence for the pentapeptide that is formed by the following reaction sequence?

Accepted Answer

A)  Ser-Thr-Pro-Lys-Leu 
B)  Leu-Lys-Pro-Thr-Ser 
C)  Thr-Thr- Pro-Lys-Leu 
D)  Leu-Lys-Pro-Thr-Thr 
E)  none of these 
A)  Ser-Thr-Pro-Lys-Leu 
B)  Leu-Lys-Pro-Thr-Ser 
C)  Thr-Thr- Pro-Lys-Leu 
D)  Leu-Lys-Pro-Thr-Thr 
E)  none of these

Question 2

Which of the following amino acids have an acidic side chain?

Accepted Answer

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

Question 3

Which of the following is a correct bond-line structure for the tripeptide Val-Asp-Ala?

Accepted Answer

A)  I 
B)  II 
C)  III 
D)  IV 
E)  none of these 
A)  I 
B)  II 
C)  III 
D)  IV 
E)  none of these

Question 4

Which of the following tripeptides is formed when alanine is treated with (BoC)2O and proline is treated with benzyl alcohol/acid first and the resulting intermediates are reacted in the presence of DCC followed by treatment with aqueous NaOH. The dipeptide is then reacted with the benzyl ester of leucine in the presence of DCC followed by treatment with trifluoroacetic acid and then aqueous NaOH?

Accepted Answer

A)  Ala-Pro-Leu 
B)  Pro-Ala-Leu 
C)  Leu-Ala-Pro 
D)  Pro-Leu-Ala 
E)  all of these 
A)  Ala-Pro-Leu 
B)  Pro-Ala-Leu 
C)  Leu-Ala-Pro 
D)  Pro-Leu-Ala 
E)  all of these

Question 5

Which of the following tripeptides is formed when serine is treated with (BoC)2O and threonine is treated with benzyl alcohol/acid first and the resulting intermediates are reacted in the presence of DCC followed by treatment with aqueous NaOH. The dipeptide is then reacted with the benzyl ester of isoleucine in the presence of DCC followed by treatment with trifluoroacetic acid and then aqueous NaOH?

Accepted Answer

A)  Ser-Tyr-Ile 
B)  Ser-Thr-Ile 
C)  Ile-Ser-Thr 
D)  Ile-Ser-Tyr 
E)  none of these 
A)  Ser-Tyr-Ile 
B)  Ser-Thr-Ile 
C)  Ile-Ser-Thr 
D)  Ile-Ser-Tyr 
E)  none of these

Question 6

Which amino acid is produced from the following reaction?

Accepted Answer

A)  methionine 
B)  serine 
C)  cysteine 
D)  lysine 
E)  none of these 
A)  methionine 
B)  serine 
C)  cysteine 
D)  lysine 
E)  none of these

Question 7

Which one of the following amino acids contain an amide side chain?

Accepted Answer

A)  cysteine 
B)  serine 
C)  glutamine 
D)  leucine 
E)  proline 
A)  cysteine 
B)  serine 
C)  glutamine 
D)  leucine 
E)  proline

Question 8

Which of the following is the predominant form of arginine at pH 2?

Accepted Answer

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

Question 9

Which of the following dipeptides is formed when tyrosine is treated with (BoC)2O and proline is treated with benzyl alcohol/acid first and the resulting intermediates are reacted in the presence of DCC followed by treatment with trifluoroacetic acid and then aqueous NaOH?

Accepted Answer

A)  Tyr-Pro 
B)  Pro-Tyr 
C)  Pro-Pro 
D)  Tyr-Tyr 
E)  all of these 
A)  Tyr-Pro 
B)  Pro-Tyr 
C)  Pro-Pro 
D)  Tyr-Tyr 
E)  all of these

Question 10

Provide the reagents necessary to synthesize the following amino acid via the amidomalonate synthesis.

Accepted Answer

The answer of Provide the reagents necessary to synthesize the...

Question 11

An amino acid can exist as a ________, which is a dipolar ion that carries both positive and negative charge.

Accepted Answer

A)  cation 
B)  anion 
C)  zwitterion 
D)  none of these 
A)  cation 
B)  anion 
C)  zwitterion 
D)  none of these

Question 12

Which of the following amino acids is the smallest?

Accepted Answer

A)  tyrosine 
B)  proline 
C)  leucine 
D)  tryptophan 
E)  glycine 
A)  tyrosine 
B)  proline 
C)  leucine 
D)  tryptophan 
E)  glycine

Question 13

Heating of proteins results in loss of activity and the process is referred to as _______.

Accepted Answer

A)  hydrolysis 
B)  denaturation 
C)  sequencing 
D)  hydrophobic interactions 
E)  covalent bonding 
A)  hydrolysis 
B)  denaturation 
C)  sequencing 
D)  hydrophobic interactions 
E)  covalent bonding

Question 14

Which of the following statements is true about $\alpha$-amino acids?

Accepted Answer

A)  the amino and carboxylic acid groups are separated by one carbon atom 
B)  the amino group is connected to a carbon atom that is $\alpha$ to the carboxylic acid group 
C)  the $\alpha$ carbon can be a chirality center 
D)  all of these are true 
A)  the amino and carboxylic acid groups are separated by one carbon atom 
B)  the amino group is connected to a carbon atom that is $\alpha$ to the carboxylic acid group 
C)  the $\alpha$ carbon can be a chirality center 
D)  all of these are true

Question 15

Chymotrypsin, a digestive enzyme, catalyzes the hydrolysis of the peptide bond at the carboxyl end of which of the following amino acids?

Accepted Answer

A)  phenylalanine 
B)  tyrosine 
C)  tryptophan 
D)  histidine 
E)  A, B and C 
A)  phenylalanine 
B)  tyrosine 
C)  tryptophan 
D)  histidine 
E)  A, B and C

Question 16

Provide the reagents necessary to prepare cysteine using a Strecker synthesis.

Accepted Answer

The answer of Provide the reagents necessary to prepare cysteine...

Question 17

Which of the following side chain interactions results in the tertiary structure of a protein?

Accepted Answer

A)  hydrogen bonding 
B)  salt bridges 
C)  disulfide linkages 
D)  hydrophobic interactions 
E)  all of these 
A)  hydrogen bonding 
B)  salt bridges 
C)  disulfide linkages 
D)  hydrophobic interactions 
E)  all of these

Question 18

Provide the structure of the amino acid produced from the following reaction sequence.

Accepted Answer

The answer of Provide the structure of the amino acid...

Question 19

Which of the following fragments are formed when the following peptide is cleaved using trypsin? Gly-Lys-Cys-Phe-Ile-Val-Tyr-Ala-Ser

Accepted Answer

A)  Gly, Lys-Cys, Phe-Ile-Val, Tyr-Ala-Ser 
B)  Gly -Lys, Cys-Phe-Ile-Val-Tyr-Ala-Ser 
C)  Gly-Lys-Cys- Phe, Ile-Val-Tyr-Ala-Ser 
D)  Gly-Lys, Cys, Phe-Ile- Val, Tyr-Ala-Ser 
E)  Gly-Lys-Cys-Phe, Ile-Val-Tyr-Ala- Ser 
A)  Gly, Lys-Cys, Phe-Ile-Val, Tyr-Ala-Ser 
B)  Gly -Lys, Cys-Phe-Ile-Val-Tyr-Ala-Ser 
C)  Gly-Lys-Cys- Phe, Ile-Val-Tyr-Ala-Ser 
D)  Gly-Lys, Cys, Phe-Ile- Val, Tyr-Ala-Ser 
E)  Gly-Lys-Cys-Phe, Ile-Val-Tyr-Ala- Ser

Question 20

Which of the following amino acids will migrate towards the cathode at pH 7?
Glycine: pI = 6.0
Lysine: pI = 9.7

Accepted Answer

The answer of Which of the following amino acids will...

Exam 25: Amino Acids, Peptides, and Proteins

Which of the following is the correct sequence for the pentapeptide that is formed by the following reaction sequence?

Which of the following amino acids have an acidic side chain?

Which of the following is a correct bond-line structure for the tripeptide Val-Asp-Ala?

Which amino acid is produced from the following reaction?

Which one of the following amino acids contain an amide side chain?

Which of the following is the predominant form of arginine at pH 2?

Which of the following dipeptides is formed when tyrosine is treated with (BoC)2O and proline is treated with benzyl alcohol/acid first and the resulting intermediates are reacted in the presence of DCC followed by treatment with trifluoroacetic acid and then aqueous NaOH?

Provide the reagents necessary to synthesize the following amino acid via the amidomalonate synthesis.

An amino acid can exist as a ________, which is a dipolar ion that carries both positive and negative charge.

Which of the following amino acids is the smallest?

Heating of proteins results in loss of activity and the process is referred to as _______.

Which of the following statements is true about α\alphaα -amino acids?

Chymotrypsin, a digestive enzyme, catalyzes the hydrolysis of the peptide bond at the carboxyl end of which of the following amino acids?

Provide the reagents necessary to prepare cysteine using a Strecker synthesis.

Which of the following side chain interactions results in the tertiary structure of a protein?

Provide the structure of the amino acid produced from the following reaction sequence.

Which of the following fragments are formed when the following peptide is cleaved using trypsin? Gly-Lys-Cys-Phe-Ile-Val-Tyr-Ala-Ser

Which of the following amino acids will migrate towards the cathode at pH 7? Glycine: pI = 6.0 Lysine: pI = 9.7

A Review of General Chemistry: Electrons, Bonds, and Molecular Properties

Molecular Representations

Acids and Bases

Alkanes and Cycloalkanes

Stereoisomerism

Chemical Reactivity and Mechanisms

Alkyl Halides: Nucleophilic Substitution and Elimination Reactions

Addition Reactions of Alkenes

Alkynes

Radical Reactions

Synthesis

Alcohols and Phenols

Ethers and Epoxides; Thiols and Sulfides

Infrared Spectroscopy and Mass Spectrometry

Nuclear Magnetic Resonance Spectroscopy

Conjugated Pi Systems and Pericyclic Reactions

Aromatic Compounds

Aromatic Substitution Reactions

Aldehydes and Ketones

Carboxylic Acids and Their Derivatives

Alpha Carbon Chemistry: Enols and Enolates

Amines

Introduction to Organometallic Compounds

Carbohydrates

Lipids

Synthetic Polymers

Filters

Which of the following dipeptides is formed when tyrosine is treated with (BoC)₂O and proline is treated with benzyl alcohol/acid first and the resulting intermediates are reacted in the presence of DCC followed by treatment with trifluoroacetic acid and then aqueous NaOH?

Which of the following statements is true about $\alpha$ -amino acids?