Question 1

Exhibit 4B   Refer to Exhibit 4B.Which one shows hydrogen bonding of the peptide backbone?

Accepted Answer

A)  M 
B)  N 
C)  P 
D)  M and N 
E)  All of these 
A)  M 
B)  N 
C)  P 
D)  M and N 
E)  All of these

Question 2

Why does myoglobin have a histidine that prevents both O2 and CO from binding perpendicularly to the heme plane?

Accepted Answer

A)  This increases myoglobin's affinity for O2. 
B)  This increases myoglobin's affinity for CO. 
C)  This lessens the difference in myoglobin's affinity for CO versus O2. 
D)  This prevents the iron of the heme from being oxidized. 
A)  This increases myoglobin's affinity for O2. 
B)  This increases myoglobin's affinity for CO. 
C)  This lessens the difference in myoglobin's affinity for CO versus O2. 
D)  This prevents the iron of the heme from being oxidized.

Question 3

Which of the following is true?

Accepted Answer

A)  The peptide bonds in the b-sheet are extended. 
B)  The peptide bonds in the a-helix coil back on themselves. 
C)  Both a-helices and b-sheets can be found as part of tertiary structure. 
D)  All of these 
A)  The peptide bonds in the b-sheet are extended. 
B)  The peptide bonds in the a-helix coil back on themselves. 
C)  Both a-helices and b-sheets can be found as part of tertiary structure. 
D)  All of these

Question 4

The structure of myoglobin consists

Accepted Answer

A)  almost entirely of a-helices. 
B)  almost entirely of b-sheets. 
C)  of a mixture of a-helices and b-sheets. 
D)  of a unique secondary motif that is neither a-helix nor b-sheet. 
A)  almost entirely of a-helices. 
B)  almost entirely of b-sheets. 
C)  of a mixture of a-helices and b-sheets. 
D)  of a unique secondary motif that is neither a-helix nor b-sheet.

Question 5

In what oxidation state must the iron atom be for heme to bind oxygen?

Accepted Answer

A)  0, Fe(0) 
B)  1+, Fe(I) 
C)  2+, Fe(II) 
D)  3+, Fe(III) 
E)  There is no required oxidation state for the iron. 
A)  0, Fe(0) 
B)  1+, Fe(I) 
C)  2+, Fe(II) 
D)  3+, Fe(III) 
E)  There is no required oxidation state for the iron.

Question 6

The overall folding of a single protein subunit is called:

Accepted Answer

A)  primary structure 
B)  secondary structure 
C)  tertiary structure 
D)  quaternary structure 
E)  All of these 
A)  primary structure 
B)  secondary structure 
C)  tertiary structure 
D)  quaternary structure 
E)  All of these

Question 7

The affinity of fetal hemoglobin for oxygen

Accepted Answer

A)  has not been studied 
B)  is the same as that of adult hemoglobin 
C)  is lower than that of maternal hemoglobin 
D)  is higher than that of maternal hemoglobin 
A)  has not been studied 
B)  is the same as that of adult hemoglobin 
C)  is lower than that of maternal hemoglobin 
D)  is higher than that of maternal hemoglobin

Question 8

Exhibit 4B   Refer to Exhibit 4B.Which one shows covalent bonding of R-groups?

Accepted Answer

A)  K 
B)  L 
C)  O 
D)  K and L 
E)  All of these 
A)  K 
B)  L 
C)  O 
D)  K and L 
E)  All of these

Question 9

Which of the following forces are involved in maintaining the primary structure of a protein?

Accepted Answer

A)  covalent bonds 
B)  hydrogen bonds 
C)  ionic interactions 
D)  hydrophobic interactions 
A)  covalent bonds 
B)  hydrogen bonds 
C)  ionic interactions 
D)  hydrophobic interactions

Question 10

Which of the following is not true?

Accepted Answer

A)  The heme group of myoglobin is held in place only through non-covalent bonding. 
B)  The F8 histidine is important to the function of myoglobin 
C)  The E7 histidine is important to the function of myoglobin 
D)  Myoglobin and hemoglobin differ only in one amino acid 
A)  The heme group of myoglobin is held in place only through non-covalent bonding. 
B)  The F8 histidine is important to the function of myoglobin 
C)  The E7 histidine is important to the function of myoglobin 
D)  Myoglobin and hemoglobin differ only in one amino acid

Question 11

The oxygen binding curve of which of the following is the closest to that of myoglobin?

Accepted Answer

A)  hemoglobin at pH 6.8 
B)  hemoglobin that lacks BPG 
C)  maternal hemoglobin 
D)  fetal hemoglobin 
A)  hemoglobin at pH 6.8 
B)  hemoglobin that lacks BPG 
C)  maternal hemoglobin 
D)  fetal hemoglobin

Question 12

Which of the following is often found connecting the strands of an antiparallel b-sheet?

Accepted Answer

A)  b-bulge 
B)  reverse turn 
C)  a-helix 
D)  prosthetic group 
A)  b-bulge 
B)  reverse turn 
C)  a-helix 
D)  prosthetic group

Question 13

Domains are

Accepted Answer

A)  independently folded regions of proteins 
B)  the a-helical portions of proteins 
C)  the b-pleated regions of proteins 
D)  all of the above 
A)  independently folded regions of proteins 
B)  the a-helical portions of proteins 
C)  the b-pleated regions of proteins 
D)  all of the above

Question 14

Which of the following best describes a motif?

Accepted Answer

A)  a repetitive supersecondary structure 
B)  a common nonrepetitive irregularity found in antiparallel b-sheets 
C)  a protein conformation with biological activity 
D)  a group of atoms other than an amino acid 
A)  a repetitive supersecondary structure 
B)  a common nonrepetitive irregularity found in antiparallel b-sheets 
C)  a protein conformation with biological activity 
D)  a group of atoms other than an amino acid

Question 15

Which of the following statements regarding hydrogen bonding in secondary structures is true?

Accepted Answer

A)  Both a-helices and b-sheets only use intrachain hydrogen bonds. 
B)  Both a-helices and b-sheets only use interchain hydrogen bonds. 
C)  a-helices only use intrachain hydrogen bonds and b-sheets can use either intrachain or interchain hydrogen bonds. 
D)  a-helices can use either intrachain or interchain hydrogen bonds and b-sheets only use interchain hydrogen bonds. 
A)  Both a-helices and b-sheets only use intrachain hydrogen bonds. 
B)  Both a-helices and b-sheets only use interchain hydrogen bonds. 
C)  a-helices only use intrachain hydrogen bonds and b-sheets can use either intrachain or interchain hydrogen bonds. 
D)  a-helices can use either intrachain or interchain hydrogen bonds and b-sheets only use interchain hydrogen bonds.

Question 16

A single amino substitution can give rise to a malfunctioning protein.

Accepted Answer

A) True 
 B)False

Question 17

Proteins that aid in the correct and timely folding of other proteins are called

Accepted Answer

A)  motifs. 
B)  chaperones. 
C)  liposomes. 
D)  cooperative. 
A)  motifs. 
B)  chaperones. 
C)  liposomes. 
D)  cooperative.

Exam 4: The Three-Dimensional Structure of Proteins

Exhibit 4B Refer to Exhibit 4B.Which one shows hydrogen bonding of the peptide backbone?

Why does myoglobin have a histidine that prevents both O2 and CO from binding perpendicularly to the heme plane?

Which of the following is true?

The structure of myoglobin consists

In what oxidation state must the iron atom be for heme to bind oxygen?

The overall folding of a single protein subunit is called:

The affinity of fetal hemoglobin for oxygen

Exhibit 4B Refer to Exhibit 4B.Which one shows covalent bonding of R-groups?

Which of the following forces are involved in maintaining the primary structure of a protein?

Which of the following is not true?

The oxygen binding curve of which of the following is the closest to that of myoglobin?

Which of the following is often found connecting the strands of an antiparallel b-sheet?

Domains are

Which of the following best describes a motif?

Which of the following statements regarding hydrogen bonding in secondary structures is true?

A single amino substitution can give rise to a malfunctioning protein.

Proteins that aid in the correct and timely folding of other proteins are called

Biochemistry and the Organization of Cells

Water: The Solvent for Biochemical Reactions

Amino Acids and Peptides

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

Why does myoglobin have a histidine that prevents both O₂ and CO from binding perpendicularly to the heme plane?