Question 1

Which of the following dipeptides is L−Ser−L−Phe?

Accepted Answer

A) 
  
B) 
  
C) 
  
D) 
  
A) 
  
B) 
  
C) 
  
D)

Question 2

Which of the following reagents can be used to cleave a tert-butoxycarbonyl (Boc) protecting group from a peptide?

Accepted Answer

A)  H2/Pd 
B)  CF3CO2H 
C)  Na2CO3, H2O 
D)  LiAlH4 
A)  H2/Pd 
B)  CF3CO2H 
C)  Na2CO3, H2O 
D)  LiAlH4

Question 3

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 chymotropsin?

Accepted Answer

Chymotropsin catalyzes the hydrolysis of

Question 4

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 5

Match a term from the list below to each definition.
-Enzymes which catalyze the bonding together of two substrates.

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 6

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 7

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 pKS1U1B1a1S1U1B0 = 2.36 and pKS1U1B1a2S1U1B0 = 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 Refer to the data below to answer...

Question 8

Which of the following tripeptides is not hydrolysed by trypsin?

Accepted Answer

A)  Glu−Arg−Ser 
B)  Arg−Glu−Thr 
C)  Glu−Ser−Arg 
D)  Lys−Ser−Arg 
A)  Glu−Arg−Ser 
B)  Arg−Glu−Thr 
C)  Glu−Ser−Arg 
D)  Lys−Ser−Arg

Question 9

Identify the aldehyde byproduct that results from the following reaction.

Accepted Answer

The answer of Identify the aldehyde byproduct that results from...

Question 10

Refer to the data below to answer the following question.Amino Acid
Isoelectric point
Arginine
10.76
Glutamic Acid
3.22
Tryptophan
5.89
-Define isoelectric point.

Accepted Answer

The isoelectric point is the p

Question 11

What are the R/S designations of the two stereocenters of L-threonine?

Accepted Answer

A)  2R,3R 
B)  2R,3S 
C)  2S,3R 
D)  2S,3S 
A)  2R,3R 
B)  2R,3S 
C)  2S,3R 
D)  2S,3S

Question 12

Draw the structure of the product of the following reaction and describe the usefulness of this type of reaction.

Accepted Answer

@#IMG-DLM& Removal of a protecting group

Question 13

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. Show the steps involved in a synthesis of F−G−I using the Merrifield procedure.

Accepted Answer

1. @#IMG-DLM& @#IMG-DLM& @#IMG-DLM& "2.BOC−I + ClCH₂Polymer @#IMG-DLM& BOC−I−O−CH

Question 14

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 15

An enzyme classified as a ligase would be associated with a reaction than involves the:

Accepted Answer

A)  introduction of a double bond. 
B)  loss of water. 
C)  loss of carbon dioxide. 
D)  transfer of an amino group. 
E)  hydrolysis of an ester. 
A)  introduction of a double bond. 
B)  loss of water. 
C)  loss of carbon dioxide. 
D)  transfer of an amino group. 
E)  hydrolysis of an ester.

Question 16

Refer to the data below to answer the following question.Amino Acid
Isoelectric point
Arginine
10.76
Glutamic Acid
3.22
Tryptophan
5.89
-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 17

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 pKS1U1B1a1S1U1B0 = 2.36 and pKS1U1B1a2S1U1B0 = 9.60.
-Refer to instructions. Draw a Fischer projection of L-leucine and label the chirality center(s) as R or S.

Accepted Answer

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

Question 18

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 19

Which of the following amino acids has a non-polar side chain?

Accepted Answer

A)  histidine 
B)  arginine 
C)  glutamine 
D)  valine 
A)  histidine 
B)  arginine 
C)  glutamine 
D)  valine

Question 20

To what structural feature does the term "quaternary 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

Exam 19: Biomolecules: Amino Acids, Peptides, and Proteins

Which of the following dipeptides is L−Ser−L−Phe?

Which of the following reagents can be used to cleave a tert-butoxycarbonyl (Boc) protecting group from a peptide?

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.

Match a term from the list below to each definition. -Enzymes which catalyze the bonding together of two substrates.

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

Which of the following tripeptides is not hydrolysed by trypsin?

Identify the aldehyde byproduct that results from the following reaction.

Refer to the data below to answer the following question.Amino Acid Isoelectric point Arginine 10.76 Glutamic Acid 3.22 Tryptophan 5.89 -Define isoelectric point.

What are the R/S designations of the two stereocenters of L-threonine?

Draw the structure of the product of the following reaction and describe the usefulness of this type of reaction.

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

An enzyme classified as a ligase would be associated with a reaction than involves the:

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 a Fischer projection of L-leucine and label the chirality center(s) as R or S.

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

Which of the following amino acids has a non-polar side chain?

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

Structure and Bonding

Polar Covalent Bonds; Acids and Bases

Organic Compounds: Alkanes and Their Stereochemistry

Organic Compounds: Cycloalkanes and Their Stereochemistry

Stereochemistry at Tetrahedral Centers

An Overview of Organic Reactions

Alkenes and Alkynes

Reactions of Alkenes and Alkynes

Aromatic Compounds

Structure Determination: Mass Spectrometry, Infrared Spectroscopy, and Ultraviolet Spectroscopy

Structure Determination: Mass Spectrometry, Infrared Spectroscopy, and Ultraviolet Spectroscopy

Structure Determination: Nuclear Magnetic Resonance Spectroscopy

Organohalides: Nucleophilic Substitutions and Eliminations

Alcohols, Phenols, and Thiols; Ethers and Sulfides

Aldehydes and Ketones: Nucleophilic Addition Reactions

Carboxylic Acids and Nitriles

Carboxylic Acid Derivatives: Nucleophilic Acyl Substitution Reactions

Carbonyl Alpha-Substitution and Condensation Reactions

Amines and Heterocycles

Amino Acid Metabolism

Biomolecules: Carbohydrates

Carbohydrate Metabolism

Biomolecules: Lipids and Their Metabolism

Biomolecules: Nucleic Acids and Their Metabolism

Orbitals and Organic Chemistry: Pericyclic Reactionse

Synthetic Polymerse

Filters

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 pK_a1 = 2.36 and pK_a2 = 9.60. -Refer to instructions. Draw a Fischer projection of L-leucine and label the chirality center(s) as R or S.