Question 1

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.F) All of the above
G) B) and C)

Question 2

Describe the recurring structure called the globin fold.

Accepted Answer

Each of the four subunits of h...

Question 3

What is metmyoglobin?

Accepted Answer

Metmyoglobin is formed when the heme iro...

Question 4

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 5

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

Accepted Answer

A)    α\alphaα -thalassemia
B)    β\betaβ -thalassemia
C)   hemoglobin SC disease
D)   hemolytic anemia
E)   sickle-cell anemia F) D) and E)
G) B) and E)

Question 6

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.F) A) and C)
G) D) and E)

Question 7

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.F) A) and D)
G) None of the above

Question 8

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.F) A) and B)
G) A) and C)

Question 9

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.F) All of the above
G) A) and D) D

Question 10

What molecule stores oxygen in muscle cells?

Accepted Answer

A)   individual  α\alphaα  subunits of hemoglobin
B)   individual  β\betaβ  subunits of hemoglobin
C)   myoglobin
D)   metmyoglobin
E)   carboxyhemoglobin F) A) and D)
G) C) and D)

Question 11

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.F) A) and E)
G) A) and D) D

Question 12

Why is it advantageous for hemoglobin to have allosteric properties?

Accepted Answer

Hemoglobin binds oxygen in a positive co...

Question 13

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.F) C) and E)
G) A) and D)

Question 14

Which of the following is correct concerning the following equilibrium?
 CO2 + H2O 2 + H2O   H2CO3 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." class="answers-bank-image d-inline" rel="preload" > 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.F) A) and B)
G) B) and C)

Question 15

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...

Question 16

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.F) A) and B)
G) B) and D)

Question 17

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 18

Describe the chemical basis of the Bohr effect.

Accepted Answer

The effect observed by Christian Bohr is...

Question 19

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

Accepted Answer

Fetal hemoglobin contains two

and two

c...

Question 20

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

Accepted Answer

Bohr effect

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

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

Correct AnswerverifiedShow Answer

Describe the recurring structure called the globin fold.

Correct AnswerverifiedEach of the four subunits of h...View AnswerShow Answer

What is metmyoglobin?

Correct AnswerverifiedMetmyoglobin is formed when the heme iro...View AnswerShow Answer

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.

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Sickle-cell anemia is caused by

Correct AnswerverifiedD

What molecule stores oxygen in muscle cells?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedD

Why is it advantageous for hemoglobin to have allosteric properties?

Correct AnswerverifiedHemoglobin binds oxygen in a positive co...View AnswerShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Carbon dioxide forms carbamate groups in proteins by reaction with

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Describe the chemical basis of the Bohr effect.

Correct AnswerverifiedThe effect observed by Christian Bohr is...View AnswerShow Answer

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

Correct AnswerverifiedFetal hemoglobin contains two and two c...View AnswerShow Answer

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

Correct AnswerverifiedBohr effect

Correct Answer
verified

Correct Answer
verified
Each of the four subunits of h...
View Answer

Correct Answer
verified
Metmyoglobin is formed when the heme iro...
View Answer

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.

Correct Answer
verified

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

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
D

Correct Answer
verified

Correct Answer
verified
D

Correct Answer
verified
Hemoglobin binds oxygen in a positive co...
View Answer

Correct Answer
verified

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

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
The effect observed by Christian Bohr is...
View Answer

Correct Answer
verified
Fetal hemoglobin contains two and two c...
View Answer

Correct Answer
verified
Bohr effect