Question 1

Which of the following tripeptides is not hydrolysed by chymotrypsin?

Accepted Answer

A)  Phe-Lys-Glu 
B)  Lys-Tyr-Phe 
C)  Gln-Ser-Phe 
D)  Gln-Tyr-Ser 
A)  Phe-Lys-Glu 
B)  Lys-Tyr-Phe 
C)  Gln-Ser-Phe 
D)  Gln-Tyr-Ser C

Question 2

Instructions: Refer to the data below to answer the following question(s).
Leucine is an essential amino acid with the systematic name 2-amino-3-methylpentanoic acid. It has pKa1 = 2.36 and pKa2 = 9.60.
-Refer to instructions. What is the pI of leucine?

Accepted Answer

The pI is the isoelectric point and is the average of pK_a1 and pK_a2. For leucine:

Question 3

Which of the following amino acids migrates to the positive electrode on paper electrophoresis at a pH of 7.0?

Accepted Answer

A)  glutamic acid 
B)  arginine 
C)  lysine 
D)  histadine 
A)  glutamic acid 
B)  arginine 
C)  lysine 
D)  histadine A

Question 4

Instructions: Match a structure from the list below to each of the following terms.

-A peptide coupling reagent.

Accepted Answer

A)   
B)   
C) Val-Phe-Leu-Met-Tyr-Pro-Gly-Trp-Cys-Glu 
D)   
E)   
F)Asp-Tyr-Ile-His-Pro-Phe-Arg-Val
G)apoenzyme
H)  
I)  
J)  
K) 
L)Val-Lys-Phe-Gly-Arg-Met-Arg-Phe
M)vitamins 
A)   
B)   
C) Val-Phe-Leu-Met-Tyr-Pro-Gly-Trp-Cys-Glu 
D)   
E)   
F)Asp-Tyr-Ile-His-Pro-Phe-Arg-Val
G)apoenzyme
H)  
I)  
J)  
K) 
L)Val-Lys-Phe-Gly-Arg-Met-Arg-Phe
M)vitamins

Question 5

Instructions: Match a structure from the list below to each of the following terms.

-A polypeptide which gives four fragments on treatment with chymotrypsin.

Accepted Answer

A)   
B)   
C) Val-Phe-Leu-Met-Tyr-Pro-Gly-Trp-Cys-Glu 
D)   
E)   
F)Asp-Tyr-Ile-His-Pro-Phe-Arg-Val
G)apoenzyme
H)  
I)  
J)  
K) 
L)Val-Lys-Phe-Gly-Arg-Met-Arg-Phe
M)vitamins 
A)   
B)   
C) Val-Phe-Leu-Met-Tyr-Pro-Gly-Trp-Cys-Glu 
D)   
E)   
F)Asp-Tyr-Ile-His-Pro-Phe-Arg-Val
G)apoenzyme
H)  
I)  
J)  
K) 
L)Val-Lys-Phe-Gly-Arg-Met-Arg-Phe
M)vitamins

Question 6

Instructions: Refer to the data below to answer the following question(s).
Porcine dynorphin is a neuropeptide having 17 amino acid residues. Its structure is shown below.
Tyr-Gly-Gly-Phe-Leu-Arg-Arg-Ile-Arg-Pro-Lys-Leu-Lys-Trp-Asp-Asn-Gln
-Refer to instructions. What fragments would result if dynorphin were cleaved by trypsin?

Accepted Answer

Trypsin catalyzes the hydrolysis of pept

Question 7

Instructions: Match a structure from the list below to each of the following terms.

-An amino acid with a protected carboxyl group.

Accepted Answer

A)   
B)   
C) Val-Phe-Leu-Met-Tyr-Pro-Gly-Trp-Cys-Glu 
D)   
E)   
F)Asp-Tyr-Ile-His-Pro-Phe-Arg-Val
G)apoenzyme
H)  
I)  
J)  
K) 
L)Val-Lys-Phe-Gly-Arg-Met-Arg-Phe
M)vitamins 
A)   
B)   
C) Val-Phe-Leu-Met-Tyr-Pro-Gly-Trp-Cys-Glu 
D)   
E)   
F)Asp-Tyr-Ile-His-Pro-Phe-Arg-Val
G)apoenzyme
H)  
I)  
J)  
K) 
L)Val-Lys-Phe-Gly-Arg-Met-Arg-Phe
M)vitamins

Question 8

BOC protecting groups are generally removed by treatment with trifluoroacetic acid.   On the structures provided below, draw arrows consistent with electron flow in the mechanism of this reaction.

Accepted Answer

The answer of BOC protecting groups are generally removed by...

Question 9

Which of the following amino acids has an aromatic side chain?

Accepted Answer

A)  isoleucine 
B)  valine 
C)  tyrosine 
D)  threonine 
A)  isoleucine 
B)  valine 
C)  tyrosine 
D)  threonine

Question 10

Which of the following amino acids would contain the highest concentration of zwitterions at pH 5.90?

Accepted Answer

A)  aspartic acid (pI 2.77) 
B)  alanine (pI 6.01) 
C)  lysine (pI 9.74) 
D)  glutamic acid (pI 3.22) 
E)  all of these contain approximately equal concentrations of zwitterions 
A)  aspartic acid (pI 2.77) 
B)  alanine (pI 6.01) 
C)  lysine (pI 9.74) 
D)  glutamic acid (pI 3.22) 
E)  all of these contain approximately equal concentrations of zwitterions

Question 11

Instructions: Consider the following structure. Based on this structure answer the following question(s).  
-Refer to instructions. Identify the C-terminal amino acid and the N-terminal amino acid.

Accepted Answer

The answer of Instructions: Consider the following structure. Based on...

Question 12

Which of the following amino acids is a secondary amine?

Accepted Answer

A)  proline 
B)  glutamine 
C)  histidine 
D)  aspargine 
A)  proline 
B)  glutamine 
C)  histidine 
D)  aspargine

Question 13

Match a term from the list below to each definition.

-Enzymes which catalyze the transfer of a phosphate group.

Accepted Answer

A) Ligases 
B) Fibrous proteins 
C) Conjugated protein 
D) Hydrolases 
E) Simple protein
F)Globular proteins
G)Kinases 
A) Ligases 
B) Fibrous proteins 
C) Conjugated protein 
D) Hydrolases 
E) Simple protein
F)Globular proteins
G)Kinases

Question 14

Instructions: Refer to the data below to answer the following question(s).
Leucine is an essential amino acid with the systematic name 2-amino-3-methylpentanoic acid. It has pKa1 = 2.36 and pKa2 = 9.60.
-Refer to instructions. Draw the condensed structure for leucine, and label all chirality centers with an asterisk and identify the amine as primary, secondary or tertiary.

Accepted Answer

The answer of Instructions: Refer to the data below to...

Question 15

Instructions: Match a structure from the list below to each of the following terms.

-A peptide containing eight amino acid residues with a C-terminal valine.

Accepted Answer

A)   
B)   
C) Val-Phe-Leu-Met-Tyr-Pro-Gly-Trp-Cys-Glu 
D)   
E)   
F)Asp-Tyr-Ile-His-Pro-Phe-Arg-Val
G)apoenzyme
H)  
I)  
J)  
K) 
L)Val-Lys-Phe-Gly-Arg-Met-Arg-Phe
M)vitamins 
A)   
B)   
C) Val-Phe-Leu-Met-Tyr-Pro-Gly-Trp-Cys-Glu 
D)   
E)   
F)Asp-Tyr-Ile-His-Pro-Phe-Arg-Val
G)apoenzyme
H)  
I)  
J)  
K) 
L)Val-Lys-Phe-Gly-Arg-Met-Arg-Phe
M)vitamins

Question 16

Instructions: Refer to the data below to answer the following question(s).
Leucine is an essential amino acid with the systematic name 2-amino-3-methylpentanoic acid. It has pKa1 = 2.36 and pKa2 = 9.60.
-Refer to instructions. Draw the structure of the predominant form of leucine at pH = 1.50.

Accepted Answer

The answer of Instructions: Refer to the data below to...

Question 17

Instructions: Refer to the data below to answer the following question.
 
-Refer to instructions. At what pH would you carry out an electrophoresis experiment if you wanted to separate a mixture of lysine, aspartic acid and phenylalanine? Explain.

Accepted Answer

The optimum pH for the electrophoresis o

Question 18

Which of the following amino acids has a sulfur-containing side chain?

Accepted Answer

A)  serine 
B)  cysteine 
C)  lysine 
D)  methionine 
E)  both b and d 
A)  serine 
B)  cysteine 
C)  lysine 
D)  methionine 
E)  both b and d

Question 19

To what structural feature does the term "secondary structure" refer?

Accepted Answer

A)  the sequence of amino acids in proteins 
B)  the overall folding pattern of proteins 
C)  the aggregation of polypeptides 
D)  the conformation of local regions of polypeptides 
A)  the sequence of amino acids in proteins 
B)  the overall folding pattern of proteins 
C)  the aggregation of polypeptides 
D)  the conformation of local regions of polypeptides

Question 20

Instructions: Refer to the data below to answer the following question(s).
Leucine is an essential amino acid with the systematic name 2-amino-3-methylpentanoic acid. It has pKa1 = 2.36 and pKa2 = 9.60.
-Refer to instructions. Leucine is described as an essential amino acid. What does this mean?

Accepted Answer

Humans are able to synthesize only 11 of

Which of the following tripeptides is not hydrolysed by chymotrypsin?

Instructions: Refer to the data below to answer the following question(s). Leucine is an essential amino acid with the systematic name 2-amino-3-methylpentanoic acid. It has pKa1 = 2.36 and pKa2 = 9.60. -Refer to instructions. What is the pI of leucine?

Which of the following amino acids migrates to the positive electrode on paper electrophoresis at a pH of 7.0?

Instructions: Match a structure from the list below to each of the following terms. -A peptide coupling reagent.

Instructions: Match a structure from the list below to each of the following terms. -A polypeptide which gives four fragments on treatment with chymotrypsin.

Instructions: Match a structure from the list below to each of the following terms. -An amino acid with a protected carboxyl group.

BOC protecting groups are generally removed by treatment with trifluoroacetic acid. On the structures provided below, draw arrows consistent with electron flow in the mechanism of this reaction.

Which of the following amino acids has an aromatic side chain?

Which of the following amino acids would contain the highest concentration of zwitterions at pH 5.90?

Instructions: Consider the following structure. Based on this structure answer the following question(s). -Refer to instructions. Identify the C-terminal amino acid and the N-terminal amino acid.

Which of the following amino acids is a secondary amine?

Match a term from the list below to each definition. -Enzymes which catalyze the transfer of a phosphate group.

Instructions: Match a structure from the list below to each of the following terms. -A peptide containing eight amino acid residues with a C-terminal valine.

Instructions: Refer to the data below to answer the following question(s). Leucine is an essential amino acid with the systematic name 2-amino-3-methylpentanoic acid. It has pKa1 = 2.36 and pKa2 = 9.60. -Refer to instructions. Draw the structure of the predominant form of leucine at pH = 1.50.

Instructions: Refer to the data below to answer the following question. -Refer to instructions. At what pH would you carry out an electrophoresis experiment if you wanted to separate a mixture of lysine, aspartic acid and phenylalanine? Explain.

Which of the following amino acids has a sulfur-containing side chain?

To what structural feature does the term "secondary structure" refer?

Instructions: Refer to the data below to answer the following question(s). Leucine is an essential amino acid with the systematic name 2-amino-3-methylpentanoic acid. It has pKa1 = 2.36 and pKa2 = 9.60. -Refer to instructions. Leucine is described as an essential amino acid. What does this mean?

Structure and Bonding:acids and Bases

Alkanes: the Nature of Organic Compounds

Alkenes and Alkynes: the Nature of Organic Reactions

Reactions of Alkenes and Alkynes

Aromatic Compounds

Sterechemistry at Tetrahedral Centers

Organohalides: Nucleophilic Substitutions and Eliminations

Alcohols, Phenols, Ethers, and Their Sulfur Analogs

Aldehydes and Ketones: Nucleophilic Addition Reactions

Carboxylic Acids and Derivatives: Nucleophilic Acyl Substitution Reactions

Carbonyl Alpha-Substitution Reactions and Condensation Reactions

Amines

Structure Determination

Biomolecules: Carbohydrates

Biomolecules: Lipids and Nucleic Acids

The Organic Chemistry of Metabolic Pathways

Filters

Exam 15: Biomolecules: Amino Acids, Peptides, and Proteins

Which of the following tripeptides is not hydrolysed by chymotrypsin?

Instructions: Refer to the data below to answer the following question(s). Leucine is an essential amino acid with the systematic name 2-amino-3-methylpentanoic acid. It has pKa1 = 2.36 and pKa2 = 9.60. -Refer to instructions. What is the pI of leucine?

Which of the following amino acids migrates to the positive electrode on paper electrophoresis at a pH of 7.0?

Instructions: Match a structure from the list below to each of the following terms. -A peptide coupling reagent.

Instructions: Match a structure from the list below to each of the following terms. -A polypeptide which gives four fragments on treatment with chymotrypsin.

Instructions: Match a structure from the list below to each of the following terms. -An amino acid with a protected carboxyl group.

BOC protecting groups are generally removed by treatment with trifluoroacetic acid. On the structures provided below, draw arrows consistent with electron flow in the mechanism of this reaction.

Which of the following amino acids has an aromatic side chain?

Which of the following amino acids would contain the highest concentration of zwitterions at pH 5.90?

Instructions: Consider the following structure. Based on this structure answer the following question(s). -Refer to instructions. Identify the C-terminal amino acid and the N-terminal amino acid.

Which of the following amino acids is a secondary amine?

Match a term from the list below to each definition. -Enzymes which catalyze the transfer of a phosphate group.

Instructions: Match a structure from the list below to each of the following terms. -A peptide containing eight amino acid residues with a C-terminal valine.

Instructions: Refer to the data below to answer the following question(s). Leucine is an essential amino acid with the systematic name 2-amino-3-methylpentanoic acid. It has pKa1 = 2.36 and pKa2 = 9.60. -Refer to instructions. Draw the structure of the predominant form of leucine at pH = 1.50.

Instructions: Refer to the data below to answer the following question. -Refer to instructions. At what pH would you carry out an electrophoresis experiment if you wanted to separate a mixture of lysine, aspartic acid and phenylalanine? Explain.

Which of the following amino acids has a sulfur-containing side chain?

To what structural feature does the term "secondary structure" refer?

Instructions: Refer to the data below to answer the following question(s). Leucine is an essential amino acid with the systematic name 2-amino-3-methylpentanoic acid. It has pKa1 = 2.36 and pKa2 = 9.60. -Refer to instructions. Leucine is described as an essential amino acid. What does this mean?

Structure and Bonding:acids and Bases

Alkanes: the Nature of Organic Compounds

Alkenes and Alkynes: the Nature of Organic Reactions

Reactions of Alkenes and Alkynes

Aromatic Compounds

Sterechemistry at Tetrahedral Centers

Organohalides: Nucleophilic Substitutions and Eliminations

Alcohols, Phenols, Ethers, and Their Sulfur Analogs

Aldehydes and Ketones: Nucleophilic Addition Reactions

Carboxylic Acids and Derivatives: Nucleophilic Acyl Substitution Reactions

Carbonyl Alpha-Substitution Reactions and Condensation Reactions

Amines

Structure Determination

Biomolecules: Carbohydrates

Biomolecules: Lipids and Nucleic Acids

The Organic Chemistry of Metabolic Pathways

Filters