Question 1

Which of the following statements is correct for hemoglobin and oxygen transport?

Accepted Answer

A)  The oxygen binds to the proximal histidine residue of the globin chain. 
B)  Bonding of carbon dioxide to hemoglobin molecules increases the binding of oxygen. 
C)  Hemoglobin binds more oxygen as the pH is lowered. 
D)  Hemoglobin binds more oxygen at higher BPG concentrations. 
E)  The binding of each O2 molecule to hemoglobin increases its affinity for the next O2 molecule. 
A)  The oxygen binds to the proximal histidine residue of the globin chain. 
B)  Bonding of carbon dioxide to hemoglobin molecules increases the binding of oxygen. 
C)  Hemoglobin binds more oxygen as the pH is lowered. 
D)  Hemoglobin binds more oxygen at higher BPG concentrations. 
E)  The binding of each O2 molecule to hemoglobin increases its affinity for the next O2 molecule. E

Question 2

Choose the correct answer from the list below. Not all of the answers will be used.
-____________: This is the chemical form in which most of the carbon dioxide is transported in the blood.

Accepted Answer

A) cooperative 
B) oxygen 
C) fMRI 
D) carbamate 
E) histidine
F)hyperbolic
G)myoglobin
H)bicarbonate ion
I)sickle-cell anemia
J)protoporphyrin
K)fetal
L)carbonic acid 
A) cooperative 
B) oxygen 
C) fMRI 
D) carbamate 
E) histidine
F)hyperbolic
G)myoglobin
H)bicarbonate ion
I)sickle-cell anemia
J)protoporphyrin
K)fetal
L)carbonic acid H

Question 3

Choose the correct answer from the list below. Not all of the answers will be used.
-____________: The molecule whose function is to facilitate diffusion of oxygen in muscle cells.

Accepted Answer

A) cooperative 
B) oxygen 
C) fMRI 
D) carbamate 
E) histidine
F)hyperbolic
G)myoglobin
H)bicarbonate ion
I)sickle-cell anemia
J)protoporphyrin
K)fetal
L)carbonic acid 
A) cooperative 
B) oxygen 
C) fMRI 
D) carbamate 
E) histidine
F)hyperbolic
G)myoglobin
H)bicarbonate ion
I)sickle-cell anemia
J)protoporphyrin
K)fetal
L)carbonic acid G

Question 4

Describe the role of 2,3-bisphosphoglycerate in the function of hemoglobin.

Accepted Answer

2,3-bisphosphoglycerate (2,3-BPG), is a

Question 5

What functional role does the distal histidine play in the function of myoglobin and hemoglobin?

Accepted Answer

The bonding between the iron and oxygen

Question 6

Sickle-cell anemia is caused by:

Accepted Answer

A)  a decreased production of α chains of hemoglobin. 
B)  a substitution of a glutamic acid residue for a phenylalanine residue at the β6 position. 
C)  the loss of the heme group because the proximal His is oxidized. 
D)  a substitution of a valine residue for a glutamic acid residue at the β6 position. 
E)  a substitution of glutamic acid residue for histidine at the C terminal of the α chain. 
A)  a decreased production of α chains of hemoglobin. 
B)  a substitution of a glutamic acid residue for a phenylalanine residue at the β6 position. 
C)  the loss of the heme group because the proximal His is oxidized. 
D)  a substitution of a valine residue for a glutamic acid residue at the β6 position. 
E)  a substitution of glutamic acid residue for histidine at the C terminal of the α chain.

Question 7

Which of the following describes the Bohr effect?

Accepted Answer

A)  Lowering the pH results in the release of O2 from oxyhemoglobin. 
B)  Increasing the pressure of CO2 results in the release of O2 from oxyhemoglobin. 
C)  Increasing the pH increases the T form of hemoglobin. 
D)  All of the above. 
E)  A and B. 
A)  Lowering the pH results in the release of O2 from oxyhemoglobin. 
B)  Increasing the pressure of CO2 results in the release of O2 from oxyhemoglobin. 
C)  Increasing the pH increases the T form of hemoglobin. 
D)  All of the above. 
E)  A and B.

Question 8

Which of the following is not correct concerning the oxygenation plot of proteins X and Y, shown in the graph below?

Accepted Answer

A)  Protein X exhibits tighter oxygen binding than protein Y. 
B)  Protein Y would function as a better transport protein than protein X. 
C)  Protein X exhibits cooperative binding; Y does not. 
D)  Protein X corresponds to myoglobin; protein Y corresponds to hemoglobin. 
E)  Protein Y contains multiple binding sites. 
A)  Protein X exhibits tighter oxygen binding than protein Y. 
B)  Protein Y would function as a better transport protein than protein X. 
C)  Protein X exhibits cooperative binding; Y does not. 
D)  Protein X corresponds to myoglobin; protein Y corresponds to hemoglobin. 
E)  Protein Y contains multiple binding sites.

Question 9

The effect of pH on oxygen binding of hemoglobin is referred to as the _____________.

Accepted Answer

The answer of The effect of pH on oxygen binding...

Question 10

Choose the correct answer from the list below. Not all of the answers will be used.
-____________: The type of hemoglobin that is composed of two α chains and two γ chains.

Accepted Answer

A) cooperative 
B) oxygen 
C) fMRI 
D) carbamate 
E) histidine
F)hyperbolic
G)myoglobin
H)bicarbonate ion
I)sickle-cell anemia
J)protoporphyrin
K)fetal
L)carbonic acid 
A) cooperative 
B) oxygen 
C) fMRI 
D) carbamate 
E) histidine
F)hyperbolic
G)myoglobin
H)bicarbonate ion
I)sickle-cell anemia
J)protoporphyrin
K)fetal
L)carbonic acid

Question 11

The form of hemoglobin found in the R state is called _____________.

Accepted Answer

The answer of The form of hemoglobin found in the...

Question 12

The structure of normal adult hemoglobin can be described as:

Accepted Answer

A)  a tetramer composed of four myoglobin molecules. 
B)  a tetramer composed of two αβ dimers. 
C)  a tetramer composed of two α2 and two β2dimers. 
D)  a tetramer composed of two α2 and two γ2 dimers. 
E)  None of these accurately describe hemoglobin. 
A)  a tetramer composed of four myoglobin molecules. 
B)  a tetramer composed of two αβ dimers. 
C)  a tetramer composed of two α2 and two β2dimers. 
D)  a tetramer composed of two α2 and two γ2 dimers. 
E)  None of these accurately describe hemoglobin.

Question 13

Consider the oxygen-binding profile at three different pH values of 7.6, 7.4, and 7.2.  Which statement is most correct?

Accepted Answer

A)  Curve X most likely corresponds to pH 7.2. 
B)  Curve Z most likely corresponds to pH 7.6. 
C)  Hb has a higher affinity for oxygen at the pH of curve Z. 
D)  Curve Y most likely corresponds to pH 7.4. 
E)  pH has no effect on the oxygenation of hemoglobin. 
A)  Curve X most likely corresponds to pH 7.2. 
B)  Curve Z most likely corresponds to pH 7.6. 
C)  Hb has a higher affinity for oxygen at the pH of curve Z. 
D)  Curve Y most likely corresponds to pH 7.4. 
E)  pH has no effect on the oxygenation of hemoglobin.

Question 14

Choose the correct answer from the list below. Not all of the answers will be used.
-____________: The shape of the myoglobin binding curve that shows that it is not regulated allosterically.

Accepted Answer

A) cooperative 
B) oxygen 
C) fMRI 
D) carbamate 
E) histidine
F)hyperbolic
G)myoglobin
H)bicarbonate ion
I)sickle-cell anemia
J)protoporphyrin
K)fetal
L)carbonic acid 
A) cooperative 
B) oxygen 
C) fMRI 
D) carbamate 
E) histidine
F)hyperbolic
G)myoglobin
H)bicarbonate ion
I)sickle-cell anemia
J)protoporphyrin
K)fetal
L)carbonic acid

Question 15

Hemoglobin binding of oxygen is best described as a:

Accepted Answer

A)  concerted model. 
B)  Michaelis-Menten model. 
C)  sequential model. 
D)  combination of sequential and concerted models. 
E)  None of the above. 
A)  concerted model. 
B)  Michaelis-Menten model. 
C)  sequential model. 
D)  combination of sequential and concerted models. 
E)  None of the above.

Question 16

Which of the following is not correct concerning myoglobin?

Accepted Answer

A)  The globin chain contains an extensive α-helix structure. 
B)  The heme group is bound to the globin chain by two disulfide bonds to cysteine residues. 
C)  The iron of the heme group is in the Fe+2 oxidation state. 
D)  The diameter of the iron ion decreases upon binding to oxygen. 
E)  The function of myoglobin is oxygen storage in muscle. 
A)  The globin chain contains an extensive α-helix structure. 
B)  The heme group is bound to the globin chain by two disulfide bonds to cysteine residues. 
C)  The iron of the heme group is in the Fe+2 oxidation state. 
D)  The diameter of the iron ion decreases upon binding to oxygen. 
E)  The function of myoglobin is oxygen storage in muscle.

Question 17

Which of the following is correct concerning the differences between hemoglobin and myoglobin?

Accepted Answer

A)  Both hemoglobin and myoglobin are tetrameric proteins. 
B)  Hemoglobin exhibits a hyperbolic O2 saturation curve, while myoglobin exhibits a sigmoid-shaped curve. 
C)  Hemoglobin exhibits cooperative binding of O2, while myoglobin does not. 
D)  Hemoglobin exhibits a higher degree of O2 saturation at all physiologically relevant partial pressures of O2 than does myoglobin. 
E)  All of the above. 
A)  Both hemoglobin and myoglobin are tetrameric proteins. 
B)  Hemoglobin exhibits a hyperbolic O2 saturation curve, while myoglobin exhibits a sigmoid-shaped curve. 
C)  Hemoglobin exhibits cooperative binding of O2, while myoglobin does not. 
D)  Hemoglobin exhibits a higher degree of O2 saturation at all physiologically relevant partial pressures of O2 than does myoglobin. 
E)  All of the above.

Question 18

Carbon dioxide forms carbamate groups in proteins by reaction with:

Accepted Answer

A)  aspartate residues. 
B)  cysteine residues. 
C)  N-terminal amino groups. 
D)  tyrosine residues. 
E)  heme groups. 
A)  aspartate residues. 
B)  cysteine residues. 
C)  N-terminal amino groups. 
D)  tyrosine residues. 
E)  heme groups.

Question 19

Carbon dioxide reacts with the amino-terminal groups of hemoglobin to form carbamate groups, which carry a(n) _____________ charge.

Accepted Answer

The answer of Carbon dioxide reacts with the amino-terminal groups...

Question 20

What would be the expected result of a lysine residue being substituted with a serine residue in the BPG binding site of hemoglobin?

Accepted Answer

A)  BPG would bind more tightly because of the loss of a positive charge. 
B)  BPG would bind more tightly because of the gain of a positive charge. 
C)  BPG would bind less tightly because of the loss of a positive charge. 
D)  BPG would bind less tightly because of the gain of a positive charge. 
E)  This substitution would have no effect on the binding of BPG. 
A)  BPG would bind more tightly because of the loss of a positive charge. 
B)  BPG would bind more tightly because of the gain of a positive charge. 
C)  BPG would bind less tightly because of the loss of a positive charge. 
D)  BPG would bind less tightly because of the gain of a positive charge. 
E)  This substitution would have no effect on the binding of BPG.

Exam 9: Hemoglobin: an Allosteric Protein

Which of the following statements is correct for hemoglobin and oxygen transport?

Choose the correct answer from the list below. Not all of the answers will be used. -____________: This is the chemical form in which most of the carbon dioxide is transported in the blood.

Choose the correct answer from the list below. Not all of the answers will be used. -____________: The molecule whose function is to facilitate diffusion of oxygen in muscle cells.

Describe the role of 2,3-bisphosphoglycerate in the function of hemoglobin.

What functional role does the distal histidine play in the function of myoglobin and hemoglobin?

Sickle-cell anemia is caused by:

Which of the following describes the Bohr effect?

Which of the following is not correct concerning the oxygenation plot of proteins X and Y, shown in the graph below?

The effect of pH on oxygen binding of hemoglobin is referred to as the _____________.

Choose the correct answer from the list below. Not all of the answers will be used. -____________: The type of hemoglobin that is composed of two α chains and two γ chains.

The form of hemoglobin found in the R state is called _____________.

The structure of normal adult hemoglobin can be described as:

Consider the oxygen-binding profile at three different pH values of 7.6, 7.4, and 7.2. Which statement is most correct?

Choose the correct answer from the list below. Not all of the answers will be used. -____________: The shape of the myoglobin binding curve that shows that it is not regulated allosterically.

Hemoglobin binding of oxygen is best described as a:

Which of the following is not correct concerning myoglobin?

Which of the following is correct concerning the differences between hemoglobin and myoglobin?

Carbon dioxide forms carbamate groups in proteins by reaction with:

Carbon dioxide reacts with the amino-terminal groups of hemoglobin to form carbamate groups, which carry a(n) _____________ charge.

What would be the expected result of a lysine residue being substituted with a serine residue in the BPG binding site of hemoglobin?

Biochemistry and the Unity of Life

Water, Weak Bonds, and the Generation of Order Out of Chaos

Amino Acids

Protein Three-Dimensional Structure

Techniques in Protein Biochemistry

Basic Concepts of Enzyme Action

Kinetics and Regulation

Mechanisms and Inhibitors

Carbohydrates

Lipids

Membrane Structure and Function

Signal Transduction Pathways

Digestion: Turning a Meal Into Cellular Biochemicals

Metabolism: Basic Concepts and Design

Glycolysis

Gluconeogenesis

Preparation for the Cycle

Harvesting Electrons From the Cycle

The Electron Transport Chain

The Proton-Motive Force

The Light Reactions

The Calvin Cycle

Glycogen Degradation

Glycogen Synthesis

The Pentose Phosphate Pathway

Fatty Acid Degredation

Fatty Acid Synthesis

Lipid Synthesis

Amino Acid Degradation and the Urea Cycle

Amino Acids Synthesis

Nucleotide Metabolism

The Structure of Informational Macromolecules: Dna and Rna

DNA Replication

DNA Repair and Recombination

RNA Synthesis and Regulation in Prokaryotes

Gene Expression in Eukaryotes

RNA Processing in Eukaryotes

The Genetic Code

The Mechanism of Protein Synthesis

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