Question 1

What is the predominant form of the amino acid abbreviated E at pH 7?

Accepted Answer

A)  positive 
B)  neutral 
C)  negative 
A)  positive 
B)  neutral 
C)  negative C

Question 2

What is the predominant form of the amino acid abbreviated val at pH 7?

Accepted Answer

A)  positive 
B)  neutral 
C)  negative 
A)  positive 
B)  neutral 
C)  negative B

Question 3

At its isolectric pH, glycine will have

Accepted Answer

A)  both of its ionizable functional groups dissociated. 
B)  neither of its ionizable functional groups dissociated. 
C)  only its carboxyl group dissociated. 
D)  only its amino group dissociated. 
A)  both of its ionizable functional groups dissociated. 
B)  neither of its ionizable functional groups dissociated. 
C)  only its carboxyl group dissociated. 
D)  only its amino group dissociated. A

Question 4

Exhibit 3B A titration curve.
  
-Refer to Exhibit 3B. The amino acid depicted by the titration curve is

Accepted Answer

A)  aspartic acid 
B)  histidine 
C)  lysine 
D)  tyrosine 
E)  lysine or tyrosine 
A)  aspartic acid 
B)  histidine 
C)  lysine 
D)  tyrosine 
E)  lysine or tyrosine

Question 5

Which of the following is NOT a correct combination of an amino acid, its three-letter designation, and its one-letter designation?

Accepted Answer

A)  Lysine, lys, L 
B)  Glycine, gly, G 
C)  Histidine, his, H 
D)  Tryptophan, Trp, W 
E)  Arginine, arg, R 
A)  Lysine, lys, L 
B)  Glycine, gly, G 
C)  Histidine, his, H 
D)  Tryptophan, Trp, W 
E)  Arginine, arg, R

Question 6

Which statement is true about the classification of amino acids?

Accepted Answer

A)  Alanine and valine are basic amino acids. 
B)  Lysine and arginine are acidic amino acids. 
C)  Glutamic acid and asparagine are hydrophobic amino acids. 
D)  Tryptophan and phenylalanine are aromatic amino acids. 
E)  Methionine and cysteine are hydroxyl-containing amino acids. 
A)  Alanine and valine are basic amino acids. 
B)  Lysine and arginine are acidic amino acids. 
C)  Glutamic acid and asparagine are hydrophobic amino acids. 
D)  Tryptophan and phenylalanine are aromatic amino acids. 
E)  Methionine and cysteine are hydroxyl-containing amino acids.

Question 7

Which amino acid has a polar, non-ionic R-group

Accepted Answer

A)  Glutamic Acid 
B)  Histidine 
C)  Isoleucine 
D)  Serine 
E)  Tyrosine 
A)  Glutamic Acid 
B)  Histidine 
C)  Isoleucine 
D)  Serine 
E)  Tyrosine

Question 8

The isoelectric pH of glycine is closest to

Accepted Answer

A)  pH 4 
B)  pH 6 
C)  pH 8 
D)  pH 10 
A)  pH 4 
B)  pH 6 
C)  pH 8 
D)  pH 10

Question 9

How many possible tetrapeptides can be made using all four of the amino acids D, W, F, and R?

Accepted Answer

A)  4 
B)  6 
C)  12 
D)  24 
E)  none of the choices 
A)  4 
B)  6 
C)  12 
D)  24 
E)  none of the choices

Question 10

Which of the following is true about oxytocin?

Accepted Answer

A)  it is a peptide hormone 
B)  during pregnancy the number of receptors for oxytocin increases 
C)  it is involved in stimulating the flow of milk during nursing 
D)  all of the choices 
A)  it is a peptide hormone 
B)  during pregnancy the number of receptors for oxytocin increases 
C)  it is involved in stimulating the flow of milk during nursing 
D)  all of the choices

Question 11

$$\begin{array}{l}
\text { Exhibit } \mathbf { 3 A } \text { (for this chapter) }\
\begin{array} { l l l l } 
\text { Amino acid } & \boldsymbol { \alpha } \text {-carboxyl group pK a } & \boldsymbol { \alpha } \text {-amino group pK a } & \text { R-group pK } \
\hline \text { Ala } & 2.3 & 9.7 & \
\text { Arg } & 2.2 & 9.0 & 12.5 \
\text { Asn or Gln } & 2.1 & 9.0 & 4.0 \
\text { Asp or Glu } & 2.2 & 9.8 & 8.3 \
\text { Cys } & 1.7 & 10.8 & 6.0 \
\text { His } & 1.8 & 9.2 & \
\text { Ser } & 2.2 & 9.2 & 10.1
\end{array}
\end{array}$$
-Refer to Exhibit 3A. Calculate the pI of ASN:

Accepted Answer

A)  2.5 
B)  5.0 
C)  5.5 
D)  6.0 
E)  10.7 
A)  2.5 
B)  5.0 
C)  5.5 
D)  6.0 
E)  10.7

Question 12

Which group consists only of amino acids with polar side chains?

Accepted Answer

A)  serine, threonine, and leucine 
B)  serine, threonine, and cysteine 
C)  serine, threonine, and valine 
D)  serine, threonine, and isoleucine 
A)  serine, threonine, and leucine 
B)  serine, threonine, and cysteine 
C)  serine, threonine, and valine 
D)  serine, threonine, and isoleucine

Question 13

The pKa values of the amino groups of common amino acids

Accepted Answer

A)  occur at very low pH values 
B)  occur in a range from pH 9 to pH 11 
C)  all occur at pH 8 
D)  all occur above pH 12 
A)  occur at very low pH values 
B)  occur in a range from pH 9 to pH 11 
C)  all occur at pH 8 
D)  all occur above pH 12

Question 14

Which is the correct one-letter designation for tryptophan?

Accepted Answer

A)  E 
B)  T 
C)  W 
D)  Q 
E)  none of the choices 
A)  E 
B)  T 
C)  W 
D)  Q 
E)  none of the choices

Question 15

The side chain groups of amino acids are bonded to which carbon?

Accepted Answer

A)  The α-carbon. 
B)  The β-carbon. 
C)  The carbonyl carbon. 
D)  Different amino acids have their side chains attached to different carbons. 
A)  The α-carbon. 
B)  The β-carbon. 
C)  The carbonyl carbon. 
D)  Different amino acids have their side chains attached to different carbons.

Question 16

Which amino acid has the one-letter symbol E?

Accepted Answer

A)  lysine 
B)  phenylalanine 
C)  histidine 
D)  glutamic acid 
A)  lysine 
B)  phenylalanine 
C)  histidine 
D)  glutamic acid

Question 17

Which of the following correctly describes peptide bonds?

Accepted Answer

A)  They are special type of amide bond. 
B)  They are a very stable bonds. 
C)  They are formed when water is split out from an amino group and a carboxylic acid. 
D)  They are a bond which displays resonance. 
E)  All of these 
A)  They are special type of amide bond. 
B)  They are a very stable bonds. 
C)  They are formed when water is split out from an amino group and a carboxylic acid. 
D)  They are a bond which displays resonance. 
E)  All of these

Question 18

$$\begin{array}{l}
\text { Exhibit } \mathbf { 3 A } \text { (for this chapter) }\
\begin{array} { l l l l } 
\text { Amino acid } & \boldsymbol { \alpha } \text {-carboxyl group pK a } & \boldsymbol { \alpha } \text {-amino group pK a } & \text { R-group pK } \
\hline \text { Ala } & 2.3 & 9.7 & \
\text { Arg } & 2.2 & 9.0 & 12.5 \
\text { Asn or Gln } & 2.1 & 9.0 & 4.0 \
\text { Asp or Glu } & 2.2 & 9.8 & 8.3 \
\text { Cys } & 1.7 & 10.8 & 6.0 \
\text { His } & 1.8 & 9.2 & \
\text { Ser } & 2.2 & 9.2 & 10.1
\end{array}
\end{array}$$
-Refer to Exhibit 3A. The pI of an amino acid is the pH at which it has a zero net charge. What is the increasing order of isoelectric points (low pH to high) for these three amino acids?

Accepted Answer

A)  ALA, HIS, ASP 
B)  ASP, ALA, HIS 
C)  HIS, ALA, ASP 
D)  ALA, ASL, HIS 
E)  ASP, HIS, ALA 
A)  ALA, HIS, ASP 
B)  ASP, ALA, HIS 
C)  HIS, ALA, ASP 
D)  ALA, ASL, HIS 
E)  ASP, HIS, ALA

Question 19

Which amino acid would likely be least water-soluble at pH 7.0

Accepted Answer

A)  Histidine 
B)  Isoleucine 
C)  Isoleucine or Tyrosine, you cannot tell 
D)  Serine 
E)  Tyrosine 
A)  Histidine 
B)  Isoleucine 
C)  Isoleucine or Tyrosine, you cannot tell 
D)  Serine 
E)  Tyrosine

Question 20

$$\begin{array}{l}
\text { Exhibit } \mathbf { 3 A } \text { (for this chapter) }\
\begin{array} { l l l l } 
\text { Amino acid } & \boldsymbol { \alpha } \text {-carboxyl group pK a } & \boldsymbol { \alpha } \text {-amino group pK a } & \text { R-group pK } \
\hline \text { Ala } & 2.3 & 9.7 & \
\text { Arg } & 2.2 & 9.0 & 12.5 \
\text { Asn or Gln } & 2.1 & 9.0 & 4.0 \
\text { Asp or Glu } & 2.2 & 9.8 & 8.3 \
\text { Cys } & 1.7 & 10.8 & 6.0 \
\text { His } & 1.8 & 9.2 & \
\text { Ser } & 2.2 & 9.2 & 10.1
\end{array}
\end{array}$$
-Refer to Exhibit 3A. Which one has the R-group with the highest pK?

Accepted Answer

A)  Alanine 
B)  Arginine 
C)  Histidine 
D)  Cysteine 
E)  Aspartic Acid 
A)  Alanine 
B)  Arginine 
C)  Histidine 
D)  Cysteine 
E)  Aspartic Acid

Exam 3: Amino Acids and Peptides

What is the predominant form of the amino acid abbreviated E at pH 7?

What is the predominant form of the amino acid abbreviated val at pH 7?

At its isolectric pH, glycine will have

Exhibit 3B A titration curve. -Refer to Exhibit 3B. The amino acid depicted by the titration curve is

Which of the following is NOT a correct combination of an amino acid, its three-letter designation, and its one-letter designation?

Which statement is true about the classification of amino acids?

Which amino acid has a polar, non-ionic R-group

The isoelectric pH of glycine is closest to

How many possible tetrapeptides can be made using all four of the amino acids D, W, F, and R?

Which of the following is true about oxytocin?

Exhibit (for this chapter) Amino acid -carboxyl group pK a -amino group pK a R-group pK Ala 2.3 9.7 Arg 2.2 9.0 12.5 Asn or Gln 2.1 9.0 4.0 Asp or Glu 2.2 9.8 8.3 Cys 1.7 10.8 6.0 His 1.8 9.2 Ser 2.2 9.2 10.1 -Refer to Exhibit 3A. Calculate the pI of ASN:

Which group consists only of amino acids with polar side chains?

The pKa values of the amino groups of common amino acids

Which is the correct one-letter designation for tryptophan?

The side chain groups of amino acids are bonded to which carbon?

Which amino acid has the one-letter symbol E?

Which of the following correctly describes peptide bonds?

Which amino acid would likely be least water-soluble at pH 7.0

Exhibit (for this chapter) Amino acid -carboxyl group pK a -amino group pK a R-group pK Ala 2.3 9.7 Arg 2.2 9.0 12.5 Asn or Gln 2.1 9.0 4.0 Asp or Glu 2.2 9.8 8.3 Cys 1.7 10.8 6.0 His 1.8 9.2 Ser 2.2 9.2 10.1 -Refer to Exhibit 3A. Which one has the R-group with the highest pK?

Biochemistry and the Organization of Cells

Water: the Solvent for Biochemical Reactions

The Three-Dimensional Structure of Proteins

Protein Purification and Characterization Techniques

The Behavior of Proteins: Enzymes

The Behavior of Proteins: Enzymes, Mechanisms, and Control

Lipids and Proteins Are Associated in Biological Membranes

Nucleic Acids: How Structure Conveys Information

Biosynthesis of Nucleic Acids: Replication

Transcription of the Genetic Code: Biosynthesis of RNA

Protein Synthesis: Translation of the Genetic Message

Nucleic Acid Biotechnology Techniques

Viruses, Cancer, and Immunology

The Importance of Energy Changes and Electron Transfer in Metabolism

Carbohydrates

Glycolysis

Storage Mechanisms and Control in Carbohydrate Metabolism

The Citric Acid Cycle

Electron Transport and Oxidative Phosphorylation

Lipid Metabolism

Photosynthesis

The Metabolism of Nitrogen

Integration of Metabolism: Cellular Signaling

Filters

The pK_a values of the amino groups of common amino acids