Question 1

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

Accepted Answer

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

Question 2

Chiral objects

Accepted Answer

A)  are cyclic compounds in the chair form. 
B)  are not superimposable on their mirror images. 
C)  never occur in nature. 
D)  do not form crystals. 
A)  are cyclic compounds in the chair form. 
B)  are not superimposable on their mirror images. 
C)  never occur in nature. 
D)  do not form crystals.

Question 3

The order in which amino acids are linked in peptides is given

Accepted Answer

A)  from the C-terminal to the N-terminal end 
B)  from the N-terminal to the C-terminal end 
C)  in alphabetical order 
D)  in order of increasing molecular weights of the amino acid residues 
A)  from the C-terminal to the N-terminal end 
B)  from the N-terminal to the C-terminal end 
C)  in alphabetical order 
D)  in order of increasing molecular weights of the amino acid residues

Question 4

Thr and Ser both have hydroxyls as side chains.

Accepted Answer

A) True 
 B)False

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

Asp and Glu both have amides as side chains.

Accepted Answer

A) True 
 B)False

Question 7

The side chain of Met is a poor hydrogen bond donor.

Accepted Answer

A) True 
 B)False

Question 8

Which amino acid would have the greatest negative charge at pH = 7.0?

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 9

The pKa values of the side chains of the common amino acids

Accepted Answer

A)  are always at low pH 
B)  are always at high pH 
C)  depend on the chemical nature of the side chain 
D)  are not known 
A)  are always at low pH 
B)  are always at high pH 
C)  depend on the chemical nature of the side chain 
D)  are not known

Question 10

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 11

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 12

Exhibit 3B   A titration curve.
Refer to Exhibit 3B.Which points on the graph represent pK's?

Accepted Answer

A)  1 and 7 
B)  2, 4 and 6 
C)  3 and 5 
D)  2, 3, 4, 5 and 6 
E)  The pKs cannot be determined without more information. 
A)  1 and 7 
B)  2, 4 and 6 
C)  3 and 5 
D)  2, 3, 4, 5 and 6 
E)  The pKs cannot be determined without more information.

Question 13

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 14

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

Accepted Answer

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

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 has a hydrophilic side chain?

Accepted Answer

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

Question 17

The net charge on the peptide abbreviated CAKE in a solution at pH 7 is closest to

Accepted Answer

A)  -2 
B)  -1. 
C)  0. 
D)  +1. 
A)  -2 
B)  -1. 
C)  0. 
D)  +1.

Question 18

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 19

Which amino acid is not a precursor to a neurotransmitter?

Accepted Answer

A)  Glutamic Acid 
B)  Phenylalanine 
C)  Serine 
D)  Tryptophan 
E)  Tyrosine 
A)  Glutamic Acid 
B)  Phenylalanine 
C)  Serine 
D)  Tryptophan 
E)  Tyrosine

Question 20

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

Exam 3: Amino Acids and Peptides

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

Chiral objects

The order in which amino acids are linked in peptides is given

Thr and Ser both have hydroxyls as side chains.

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

Asp and Glu both have amides as side chains.

The side chain of Met is a poor hydrogen bond donor.

Which amino acid would have the greatest negative charge at pH = 7.0?

The pKa values of the side chains of the common amino acids

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

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

Exhibit 3B A titration curve. Refer to Exhibit 3B.Which points on the graph represent pK's?

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

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

The pKa values of the amino groups of common amino acids

Which of the following has a hydrophilic side chain?

The net charge on the peptide abbreviated CAKE in a solution at pH 7 is closest to

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

Which amino acid is not a precursor to a neurotransmitter?

The isoelectric pH of glycine is closest to

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 side chains of the common amino acids

The pK_a values of the amino groups of common amino acids