Question 1

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 2

Exhibit 3A (for this chapter)   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 3

Which amino acid has the least polar R-group H?

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 4

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 5

Which of the following amino acids has a net charge of +1 at pH 4 and a net charge of 0 at pH 8?

Accepted Answer

A)  glu 
B)  arg 
C)  his 
D)  tyr 
A)  glu 
B)  arg 
C)  his 
D)  tyr

Question 6

Which of the following is an amino acid not found in proteins?

Accepted Answer

A)  asparagine 
B)  ornithine 
C)  isoleucine 
D)  proline 
A)  asparagine 
B)  ornithine 
C)  isoleucine 
D)  proline

Question 7

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 8

Which of the following amino acids has a side chain that can make hydrogen bonds to other molecules?

Accepted Answer

A)  Leu 
B)  Ser 
C)  Ala 
D)  Gly 
A)  Leu 
B)  Ser 
C)  Ala 
D)  Gly

Question 9

Exhibit 3A (for this chapter)   Refer to Exhibit 3A. The pI of the peptide ALA-GLN-ARG-SER-HIS would be:

Accepted Answer

A)  Strongly acid 
B)  Weakly acid (4-6) 
C)  About neutral (6-8) 
D)  Weakly basic (8-10) 
E)  Strongly basic 
A)  Strongly acid 
B)  Weakly acid (4-6) 
C)  About neutral (6-8) 
D)  Weakly basic (8-10) 
E)  Strongly basic

Question 10

Explain how thyroxine differs from its parent amino acid, tyrosine.

Accepted Answer

Thyroxine differs from tyrosine in a way

Question 11

Which is the C-terminal amino acid in the peptide ALA-GLN-ARG-SER-HIS?

Accepted Answer

A)  ALA 
B)  GLN 
C)  ARG 
D)  SER 
E)  HIS 
A)  ALA 
B)  GLN 
C)  ARG 
D)  SER 
E)  HIS

Question 12

Which of the following is true about uncommon amino acids?

Accepted Answer

A)  They are found in all proteins 
B)  When they are found in proteins, they are first created by modification of the parent amino acid and then incorporated into the protein 
C)  They are formed in the protein by post-translational modification of the parent amino acid 
D)  They are always based on modification of tyrosine 
E)  none of the choices 
A)  They are found in all proteins 
B)  When they are found in proteins, they are first created by modification of the parent amino acid and then incorporated into the protein 
C)  They are formed in the protein by post-translational modification of the parent amino acid 
D)  They are always based on modification of tyrosine 
E)  none of the choices

Question 13

Exhibit 3A (for this chapter)   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

Question 14

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 15

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 16

Which of the following can be considered a unique characteristic of histidine?

Accepted Answer

A)  Its side chain is attached to the alpha carbon 
B)  It has a basic side chain 
C)  It has a side chain that is chemically basic but has an acidic pKa 
D)  It is technically an "imino" acid 
A)  Its side chain is attached to the alpha carbon 
B)  It has a basic side chain 
C)  It has a side chain that is chemically basic but has an acidic pKa 
D)  It is technically an "imino" acid

Question 17

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 18

Exhibit 3A (for this chapter)   Refer to Exhibit 3A. Calculate the pI of CYS?

Accepted Answer

A)  1.7 
B)  5.0 
C)  8.3 
D)  9.6 
E)  10.8 
A)  1.7 
B)  5.0 
C)  8.3 
D)  9.6 
E)  10.8

Question 19

The peptide bond

Accepted Answer

A)  is planar 
B)  can be written as a resonance hybrid 
C)  is the basis of protein structure. 
D)  all of the above 
A)  is planar 
B)  can be written as a resonance hybrid 
C)  is the basis of protein structure. 
D)  all of the above

Question 20

Which of the following has a hydrophilic side chain?

Accepted Answer

A)  Asn 
B)  Leu 
C)  Ile 
D)  Gly 
A)  Asn 
B)  Leu 
C)  Ile 
D)  Gly

Exam 3: Amino Acids and Peptides

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

Exhibit 3A (for this chapter) Refer to Exhibit 3A. Calculate the pI of ASN:

Which amino acid has the least polar R-group H?

Which statement is true about the classification of amino acids?

Which of the following amino acids has a net charge of +1 at pH 4 and a net charge of 0 at pH 8?

Which of the following is an amino acid not found in proteins?

Which of the following correctly describes peptide bonds?

Which of the following amino acids has a side chain that can make hydrogen bonds to other molecules?

Exhibit 3A (for this chapter) Refer to Exhibit 3A. The pI of the peptide ALA-GLN-ARG-SER-HIS would be:

Explain how thyroxine differs from its parent amino acid, tyrosine.

Which is the C-terminal amino acid in the peptide ALA-GLN-ARG-SER-HIS?

Which of the following is true about uncommon amino acids?

Exhibit 3A (for this chapter) Refer to Exhibit 3A. Which one has the R-group with the highest pK?

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

The pKa values of the amino groups of common amino acids

Which of the following can be considered a unique characteristic of histidine?

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

Exhibit 3A (for this chapter) Refer to Exhibit 3A. Calculate the pI of CYS?

The peptide bond

Which of the following has a hydrophilic side chain?

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 the 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