Question 1

What would be the expected result of a Lys residue being replaced by a Ser residue in the BPG binding site of hemoglobin?

Accepted Answer

A)  BPG would bind tighter because of the loss of a positive charge. 
B)  BPG would bind tighter 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 tighter because of the loss of a positive charge. 
B)  BPG would bind tighter 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.

Question 2

What is the composition of fetal hemoglobin?

Accepted Answer

A)  two $\alpha$chains and two $\beta$ chains 
B)  two$\alpha$ chains and two $\gamma$ chains 
C)  two $\gamma$ chains and two $\beta$chains 
D)  two $\alpha$ chains and two $\delta$ chains 
E)  four $\beta$ chains 
A)  two $\alpha$chains and two $\beta$ chains 
B)  two$\alpha$ chains and two $\gamma$ chains 
C)  two $\gamma$ chains and two $\beta$chains 
D)  two $\alpha$ chains and two $\delta$ chains 
E)  four $\beta$ chains

Question 3

2,3-bisphosphoglycerate

Accepted Answer

A)  binds in the central cavity in the T-form of hemoglobin. 
B)  preferentially binds to oxyhemoglobin and stabilizes it. 
C)  binds to positively charged groups on the $\beta$subunits. 
D)  All of the answers are correct. 
E)  binds in the central cavity in the T-form of hemoglobin and binds to positively charged groups on the $\beta$subunits. 
A)  binds in the central cavity in the T-form of hemoglobin. 
B)  preferentially binds to oxyhemoglobin and stabilizes it. 
C)  binds to positively charged groups on the $\beta$subunits. 
D)  All of the answers are correct. 
E)  binds in the central cavity in the T-form of hemoglobin and binds to positively charged groups on the $\beta$subunits.

Question 4

Under normal conditions, the heme iron in myoglobin and hemoglobin is in the ____________ oxidation state.

Accepted Answer

The answer of Under normal conditions, the heme iron in...

Question 5

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 Fe2+ 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 Fe2+ 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 6

What is neuroglobin, and what is its suspected role?

Accepted Answer

Neuroglobin is expressed in th

Question 7

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

Question 8

The T-state structure of deoxyhemoglobin is stabilized through ___________________ interactions between the carbamates and positively charged amino acids at the interface between αβ dimers.

Accepted Answer

The answer of The T-state structure of deoxyhemoglobin is stabilized...

Question 9

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 10

What factor(s) influence(s) the binding of oxygen to myoglobin?

Accepted Answer

A)  the concentration of bicarbonate ion, HCO3- 
B)  the partial pressure of oxygen, pO2 
C)  the concentration of hemoglobin present 
D)  the concentration of 2,3-BPG 
E)  both the partial pressure of oxygen, pO2and the concentration of 2,3-BPG 
A)  the concentration of bicarbonate ion, HCO3- 
B)  the partial pressure of oxygen, pO2 
C)  the concentration of hemoglobin present 
D)  the concentration of 2,3-BPG 
E)  both the partial pressure of oxygen, pO2and the concentration of 2,3-BPG

Question 11

Briefly describe the cause of sickle-cell anemia.

Accepted Answer

Sickle-cell anemia is a genetic disorder

Question 12

Which of the following is a genetic disease that results from a decreased production of one of the subunits of hemoglobin?

Accepted Answer

A)  thalassemia 
B)  pernicious anemia 
C)  megaloblastic hereditary anemia 
D)  acanthocytosis 
E)  aplastic anemia 
A)  thalassemia 
B)  pernicious anemia 
C)  megaloblastic hereditary anemia 
D)  acanthocytosis 
E)  aplastic anemia

Question 13

What is the Bohr effect?

Accepted Answer

A)  the ability of hemoglobin to retain oxygen when in competition with myoglobin 
B)  the regulation of hemoglobin-binding by hydrogen ions and carbon dioxide 
C)  the alteration of hemoglobin conformation during low oxygen stress 
D)  All of the answers are correct. 
E)  None of the answers is correct. 
A)  the ability of hemoglobin to retain oxygen when in competition with myoglobin 
B)  the regulation of hemoglobin-binding by hydrogen ions and carbon dioxide 
C)  the alteration of hemoglobin conformation during low oxygen stress 
D)  All of the answers are correct. 
E)  None of the answers is correct.

Question 14

What is the role of α-hemoglobin stabilizing protein?

Accepted Answer

Four genes express the α chain, and only

Question 15

What oxidized heme protein does not reversibly bind oxygen?

Accepted Answer

A)  metmyoglobin 
B)  oxyhemoglobin 
C)  carboxyhemoglobin 
D)  leghemoglobin 
E)  None of the answers is correct. 
A)  metmyoglobin 
B)  oxyhemoglobin 
C)  carboxyhemoglobin 
D)  leghemoglobin 
E)  None of the answers is correct.

Question 16

What is thalassemia?

Accepted Answer

Thalassemia is caused by the substantial

Question 17

Draw the oxygen-binding curve of myoglobin and that of hemoglobin. Indicate the partial pressure of oxygen in the lungs and the range of pressure in tissue.

Accepted Answer

The answer of Draw the oxygen-binding curve of myoglobin and...

Question 18

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 concentration of HCO3- results in the release of O2 from oxyhemoglobin. 
C)  Increasing the pH increases the prevalence of the T-form of hemoglobin. 
D)  All of the answers are correct. 
E)  Lowering the pH and increasing the concentration of HCO3- results in the release of O2 from oxyhemoglobin . 
A)  Lowering the pH results in the release of O2 from oxyhemoglobin. 
B)  Increasing the concentration of HCO3- results in the release of O2 from oxyhemoglobin. 
C)  Increasing the pH increases the prevalence of the T-form of hemoglobin. 
D)  All of the answers are correct. 
E)  Lowering the pH and increasing the concentration of HCO3- results in the release of O2 from oxyhemoglobin .

Question 19

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

Accepted Answer

2,3-Bisphosphoglycerate, 2,3-BPG, is a r

Question 20

Describe the structure of normal adult hemoglobin.

Accepted Answer

Normal adult hemoglobin, HbA, is a tetra

Exam 7: Hemoglobin: a Portrait of a Protein in Action

What would be the expected result of a Lys residue being replaced by a Ser residue in the BPG binding site of hemoglobin?

What is the composition of fetal hemoglobin?

2,3-bisphosphoglycerate

Under normal conditions, the heme iron in myoglobin and hemoglobin is in the ____________ oxidation state.

Which of the following is NOT correct concerning myoglobin?

What is neuroglobin, and what is its suspected role?

Hemoglobin-binding of oxygen is best described as a

The T-state structure of deoxyhemoglobin is stabilized through ___________________ interactions between the carbamates and positively charged amino acids at the interface between αβ dimers.

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

What factor(s) influence(s) the binding of oxygen to myoglobin?

Briefly describe the cause of sickle-cell anemia.

Which of the following is a genetic disease that results from a decreased production of one of the subunits of hemoglobin?

What is the Bohr effect?

What is the role of α-hemoglobin stabilizing protein?

What oxidized heme protein does not reversibly bind oxygen?

What is thalassemia?

Draw the oxygen-binding curve of myoglobin and that of hemoglobin. Indicate the partial pressure of oxygen in the lungs and the range of pressure in tissue.

Which of the following describes the Bohr effect?

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

Describe the structure of normal adult hemoglobin.

Biochemistry: an Evolving Science

Protein Composition and Structure

Exploring Proteins and Proteomes

DNA, RNA, and the Flow of Genetic Information

Exploring Genes and Genomes

Exploring Evolution and Bioinformatics

Enzymes: Basic Concepts and Kinetics

Oxidative Phosphorylation

Catalytic Strategies

Regulatory Strategies

Carbohydrates

Lipids and Cell Membranes

Membrane Channels and Pumps

Signal-Transduction Pathways

Metabolism: Basic Concepts and Design

Glycolysis and Gluconeogenesis

The Citric Acid Cycle

The Light Reactions of Photosynthesis

The Calvin Cycle and the Pentose Phosphate Pathway

Glycogen Metabolism

Fatty Acid Metabolism

Protein Turnover and Amino Acid Catabolism

The Biosynthesis of Amino Acids

Nucleotide Biosynthesis

Biosynthesis of Membrane Lipids and Steroids

The Integration of Metabolism

DNA Replication, Repair, and Recombination

Rna Synthesis and Processing

Protein Synthesis

The Control of Gene Expression in Prokaryotes

The Control of Gene Expression in Eukaryotes

Sensory Systems

The Immune System

Molecular Motors

Drug Development

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