Question 1

Sickle-cell anemia is caused by

Accepted Answer

A)  a decreased production of α chains of hemoglobin. 
B)  a substitution of a Glu residue for a Phe residue at the β6 position. 
C)  the loss of the heme group because the proximal His is oxidized. 
D)  a substitution of a Val residue for a Glu residue at the β6 position. 
E)  a substitution of Glu residue for His at the C-terminal of the α chain. 
A)  a decreased production of α chains of hemoglobin. 
B)  a substitution of a Glu residue for a Phe residue at the β6 position. 
C)  the loss of the heme group because the proximal His is oxidized. 
D)  a substitution of a Val residue for a Glu residue at the β6 position. 
E)  a substitution of Glu residue for His at the C-terminal of the α chain. D

Question 2

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

Accepted Answer

Bohr effect

Question 3

What is formed when carbon dioxide reacts with the amino terminal group of deoxyhemoglobin?

Accepted Answer

A)  amide 
B)  imine 
C)  carbonate 
D)  carbamate 
E)  None of the answers is correct. 
A)  amide 
B)  imine 
C)  carbonate 
D)  carbamate 
E)  None of the answers is correct. D

Question 4

The structure of normal adult hemoglobin can be described as a tetramer composed of

Accepted Answer

A)  four myoglobin molecules. 
B)  two αβ dimers. 
C)  two α2 and two β2 dimers. 
D)  two α2 and two γ2 dimers. 
E)  None of these accurately describe hemoglobin. 
A)  four myoglobin molecules. 
B)  two αβ dimers. 
C)  two α2 and two β2 dimers. 
D)  two α2 and two γ2 dimers. 
E)  None of these accurately describe hemoglobin.

Question 5

The ability of myoglobin to bind oxygen depends on the presence of a bound prosthetic group called _____________.

Accepted Answer

The answer of The ability of myoglobin to bind oxygen...

Question 6

Describe the chemical basis of the Bohr effect.

Accepted Answer

The effect observed by Christian Bohr is

Question 7

Another reason why hemoglobin is sensitive to changes in pH is that the T-state of hemoglobin is stabilized by a salt bridge between β1 Asp 94 and the C-terminal ___________________ of the  β1  chain.

Accepted Answer

Question 8

Describe the recurring structure called the globin fold.

Accepted Answer

Each of the four subunits of h

Question 9

Which of the following is correct concerning the following equilibrium?
 CO2 + H2O   H2CO3

Accepted Answer

A)  An increase in the pressure of CO2 will result in a decrease of pH. 
B)  This reaction is catalyzed by carbonic anhydrase. 
C)  The H2CO3 dissociates to H+ and bicarbonate ion, HCO3-. 
D)  The majority of CO2 is transported to the lungs in the form of HCO3-. 
E)  All of the answers are correct. 
A)  An increase in the pressure of CO2 will result in a decrease of pH. 
B)  This reaction is catalyzed by carbonic anhydrase. 
C)  The H2CO3 dissociates to H+ and bicarbonate ion, HCO3-. 
D)  The majority of CO2 is transported to the lungs in the form of HCO3-. 
E)  All of the answers are correct.

Question 10

What type of binding is indicated by a sigmoidal-shaped binding curve?

Accepted Answer

A)  competitive 
B)  noncompetitive 
C)  uncooperative 
D)  cooperative 
E)  None of the answers is correct. 
A)  competitive 
B)  noncompetitive 
C)  uncooperative 
D)  cooperative 
E)  None of the answers is correct.

Question 11

Which of the following is correct concerning the oxygenation plot of proteins X and Y shown below?

Accepted Answer

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

Question 12

What condition results from a single point mutation of the hemoglobin $\beta$ chain, producing the HbS variant?

Accepted Answer

A)  $\alpha$-thalassemia 
B)  $\beta$-thalassemia 
C)  hemoglobin SC disease 
D)  hemolytic anemia 
E)  sickle-cell anemia 
A)  $\alpha$-thalassemia 
B)  $\beta$-thalassemia 
C)  hemoglobin SC disease 
D)  hemolytic anemia 
E)  sickle-cell anemia

Question 13

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 14

What molecule stores oxygen in muscle cells?

Accepted Answer

A)  individual $\alpha$ subunits of hemoglobin 
B)  individual $\beta$ subunits of hemoglobin 
C)  myoglobin 
D)  metmyoglobin 
E)  carboxyhemoglobin 
A)  individual $\alpha$ subunits of hemoglobin 
B)  individual $\beta$ subunits of hemoglobin 
C)  myoglobin 
D)  metmyoglobin 
E)  carboxyhemoglobin

Question 15

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 answers are correct. 
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 answers are correct.

Question 16

What is fetal hemoglobin? How does it differ from adult hemoglobin?

Accepted Answer

Fetal hemoglobin contains two @#LAT-DLM& and two @#LAT-DLM&c

Question 17

Why is it advantageous for hemoglobin to have allosteric properties?

Accepted Answer

Hemoglobin binds oxygen in a positive co

Question 18

What is metmyoglobin?

Accepted Answer

Metmyoglobin is formed when the heme iro

Question 19

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 20

In hemoglobin, the iron of the heme is bonded to the four nitrogens of porphyrin and to the proximal ______________ residue of the globin chain.

Accepted Answer

The answer of In hemoglobin, the iron of the heme...

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

Sickle-cell anemia is caused by

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

What is formed when carbon dioxide reacts with the amino terminal group of deoxyhemoglobin?

The structure of normal adult hemoglobin can be described as a tetramer composed of

The ability of myoglobin to bind oxygen depends on the presence of a bound prosthetic group called _____________.

Describe the chemical basis of the Bohr effect.

Another reason why hemoglobin is sensitive to changes in pH is that the T-state of hemoglobin is stabilized by a salt bridge between β1 Asp 94 and the C-terminal ___________________ of the β1 chain.

Describe the recurring structure called the globin fold.

Which of the following is correct concerning the following equilibrium? CO2 + H2O H2CO3

What type of binding is indicated by a sigmoidal-shaped binding curve?

Which of the following is correct concerning the oxygenation plot of proteins X and Y shown below?

What condition results from a single point mutation of the hemoglobin β\betaβ chain, producing the HbS variant?

Carbon dioxide forms carbamate groups in proteins by reaction with

What molecule stores oxygen in muscle cells?

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

What is fetal hemoglobin? How does it differ from adult hemoglobin?

Why is it advantageous for hemoglobin to have allosteric properties?

What is metmyoglobin?

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

In hemoglobin, the iron of the heme is bonded to the four nitrogens of porphyrin and to the proximal ______________ residue of the globin chain.

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

Filters

Another reason why hemoglobin is sensitive to changes in pH is that the T-state of hemoglobin is stabilized by a salt bridge between β₁ Asp 94 and the C-terminal ___________________ of the β₁ chain.

Which of the following is correct concerning the following equilibrium? CO₂ + H₂O H₂CO₃

What condition results from a single point mutation of the hemoglobin $\beta$ chain, producing the HbS variant?