Question 1

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 2

Hemoglobin differs from myoglobin because

Accepted Answer

A)  it does not have a heme group. 
B)  it is a tetramer, whereas myoglobin is a single polypeptide chain. 
C)  it does not contain any helical regions. 
D)  it contains more β-pleated sheet structure. 
A)  it does not have a heme group. 
B)  it is a tetramer, whereas myoglobin is a single polypeptide chain. 
C)  it does not contain any helical regions. 
D)  it contains more β-pleated sheet structure.

Question 3

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

Accepted Answer

A)  β-bulge 
B)  reverse turn 
C)  α-helix 
D)  prosthetic group 
A)  β-bulge 
B)  reverse turn 
C)  α-helix 
D)  prosthetic group

Question 4

Which one is not an example of supersecondary structure?

Accepted Answer

A)  the pyrrole ring 
B)  the Greek key 
C)  the β-meander 
D)  the β-barrel 
A)  the pyrrole ring 
B)  the Greek key 
C)  the β-meander 
D)  the β-barrel

Question 5

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 6

Heme would best be described as a

Accepted Answer

A)  motif. 
B)  domain. 
C)  prosthetic group. 
D)  helix. 
A)  motif. 
B)  domain. 
C)  prosthetic group. 
D)  helix.

Question 7

Which of the following statements regarding hemoglobin (Hb) and myoglobin (Mb) is true?

Accepted Answer

A)  Mb transports oxygen while Hb stores it. 
B)  Mb has quaternary structure but Hb does not. 
C)  Mb displays simple kinetics of binding while Hb displays cooperativity. 
D)  Mb binds Fe(II) while Hb binds heme. 
A)  Mb transports oxygen while Hb stores it. 
B)  Mb has quaternary structure but Hb does not. 
C)  Mb displays simple kinetics of binding while Hb displays cooperativity. 
D)  Mb binds Fe(II) while Hb binds heme.

Question 8

Assuming the oligopeptide ALPHAHELICKS forms one continuous α-helix, the carbonyl oxygen of the glutamic acid residue is hydrogen bonded to the amide nitrogen of

Accepted Answer

A)  leucine. 
B)  isoleucine. 
C)  cysteine. 
D)  lysine. 
E)  serine. 
A)  leucine. 
B)  isoleucine. 
C)  cysteine. 
D)  lysine. 
E)  serine.

Question 9

In the Bohr effect the binding of oxygen to hemoglobin

Accepted Answer

A)  is increased by the presence of Na+ 
B)  is increased by the presence of H+ and CO2 
C)  is decreased by the presence of H+ and CO2 
D)  is unchanged 
A)  is increased by the presence of Na+ 
B)  is increased by the presence of H+ and CO2 
C)  is decreased by the presence of H+ and CO2 
D)  is unchanged

Question 10

Domains are

Accepted Answer

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

Question 11

Structures which repeat over and over in secondary structure are called:

Accepted Answer

A)  primary structure 
B)  domain 
C)  supersecondary structure 
D)  prosthetic group 
E)  All of these 
A)  primary structure 
B)  domain 
C)  supersecondary structure 
D)  prosthetic group 
E)  All of these

Question 12

Exhibit 4B
  
-Refer to Exhibit 4B. The type of bonding labeled "N" in these figure is:

Accepted Answer

A)  Hydrogen bonding of the peptide backbone 
B)  Covalent bonding involving the R-groups 
C)  Hydrophobic interactions 
D)  Metal ion coordination 
E)  Electrostatic attraction 
A)  Hydrogen bonding of the peptide backbone 
B)  Covalent bonding involving the R-groups 
C)  Hydrophobic interactions 
D)  Metal ion coordination 
E)  Electrostatic attraction

Question 13

Adult hemoglobin is half saturated with oxygen at what partial pressure of oxygen?

Accepted Answer

A)  5 torr 
B)  10 torr 
C)  25 torr 
D)  50 torr 
E)  100 torr 
A)  5 torr 
B)  10 torr 
C)  25 torr 
D)  50 torr 
E)  100 torr

Question 14

Disulfide bonds in proteins occur between the side chains of which of the following amino acid residues?

Accepted Answer

A)  glutamine 
B)  lysine 
C)  cysteine 
D)  methionine 
A)  glutamine 
B)  lysine 
C)  cysteine 
D)  methionine

Question 15

Which of the following can result in protein denaturation?

Accepted Answer

A)  heat 
B)  extremes of pH 
C)  detergents 
D)  all of the above 
A)  heat 
B)  extremes of pH 
C)  detergents 
D)  all of the above

Question 16

X-ray crystallography is used to determine protein structure because

Accepted Answer

A)  it can be done on dilute solutions 
B)  it requires no calculations 
C)  the positions of all atoms can be found by this method 
D)  all of these 
A)  it can be done on dilute solutions 
B)  it requires no calculations 
C)  the positions of all atoms can be found by this method 
D)  all of these

Question 17

The location of prosthetic groups is shown in this level of structure:

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 18

The following bond forces are important in tertiary structure:

Accepted Answer

A)  Disulfide bonds 
B)  Hydrogen bonds 
C)  Hydrophobic attraction 
D)  Both hydrogen bonds and hydrophobic attraction. 
E)  All of these are important in tertiary structure 
A)  Disulfide bonds 
B)  Hydrogen bonds 
C)  Hydrophobic attraction 
D)  Both hydrogen bonds and hydrophobic attraction. 
E)  All of these are important in tertiary structure

Question 19

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.

Question 20

Which of the following amino acids is unlikely to be found in an α-helix?

Accepted Answer

A)  phenylalanine 
B)  tryptophan 
C)  proline 
D)  lysine 
A)  phenylalanine 
B)  tryptophan 
C)  proline 
D)  lysine

Exam 4: The Three-Dimensional Structure of Proteins

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

Hemoglobin differs from myoglobin because

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

Which one is not an example of supersecondary structure?

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

Heme would best be described as a

Which of the following statements regarding hemoglobin (Hb) and myoglobin (Mb) is true?

Assuming the oligopeptide ALPHAHELICKS forms one continuous α-helix, the carbonyl oxygen of the glutamic acid residue is hydrogen bonded to the amide nitrogen of

In the Bohr effect the binding of oxygen to hemoglobin

Domains are

Structures which repeat over and over in secondary structure are called:

Exhibit 4B -Refer to Exhibit 4B. The type of bonding labeled "N" in these figure is:

Adult hemoglobin is half saturated with oxygen at what partial pressure of oxygen?

Disulfide bonds in proteins occur between the side chains of which of the following amino acid residues?

Which of the following can result in protein denaturation?

X-ray crystallography is used to determine protein structure because

The location of prosthetic groups is shown in this level of structure:

The following bond forces are important in tertiary structure:

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

Which of the following amino acids is unlikely to be found in an α-helix?

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

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