Question 1

As the partial pressure of carbon dioxide increases, the affinity of oxygen binding to hemoglobin _____________.

Accepted Answer

decreases

Question 2

Which of the following is correct concerning fetal hemoglobin?

Accepted Answer

A)   Fetal hemoglobin is composed of two α and two γ subunits.
B)   Fetal hemoglobin binds 2,3-BPG more tightly than normal adult hemoglobin.
C)   Fetal hemoglobin binds oxygen less than HbA at all pO2.
D)   Fetal hemoglobin does not exist in the T form.
E)   None of the above. A

Question 3

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. B

Question 4

Use the following to answer questions
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)  histidineF) hyperbolicG) myoglobinH) bicarbonate ionI) sickle-cell anemiaJ) protoporphyrinK) fetalL) carbonic acid

Question 5

The binding of 2,3-bisphosphoglycerate to hemoglobin _____________ (increases, decreases) its affinity of oxygen binding.

Accepted Answer

The answer of The binding of 2,3-bisphosphoglycerate to hemoglobin _____________...

Question 6

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.

Question 7

Use the following to answer questions
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)  histidineF) hyperbolicG) myoglobinH) bicarbonate ionI) sickle-cell anemiaJ) protoporphyrinK) fetalL) carbonic acid

Question 8

2,3-bisphosphoglycerate binds only to the _____________ form of hemoglobin.

Accepted Answer

The answer of 2,3-bisphosphoglycerate binds only to the _____________ form...

Question 9

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.

Question 10

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 above.
E)   None of the above.

Question 11

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

Accepted Answer

The answer of What functional role does the distal histidine...

Question 12

Describe the octahedral coordination sphere of the iron ion in hemoglobin and myoglobin.

Accepted Answer

The answer of Describe the octahedral coordination sphere of the...

Question 13

Use the following to answer questions
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)  histidineF) hyperbolicG) myoglobinH) bicarbonate ionI) sickle-cell anemiaJ) protoporphyrinK) fetalL) carbonic acid

Question 14

Consider the oxygen-binding profile at three pH values: 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.

Question 15

Use the following to answer questions
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)  histidineF) hyperbolicG) myoglobinH) bicarbonate ionI) sickle-cell anemiaJ) protoporphyrinK) fetalL) carbonic acid

Question 16

Use the following to answer questions
Choose the correct answer from the list below. Not all of the answers will be used.
-____________: This method of studying hemoglobin monitors changes in magnetic fields during the binding of oxygen.

Accepted Answer

A)  cooperative
B)  oxygen
C)  fMRI
D)  carbamate
E)  histidineF) hyperbolicG) myoglobinH) bicarbonate ionI) sickle-cell anemiaJ) protoporphyrinK) fetalL) carbonic acid

Question 17

Use the concerted model to explain allosteric cooperative binding.

Accepted Answer

The answer of Use the concerted model to explain allosteric...

Question 18

Why is it advantageous for hemoglobin to have allosteric properties?

Accepted Answer

The answer of Why is it advantageous for hemoglobin to...

Question 19

Use the following to answer questions
Choose the correct answer from the list below. Not all of the answers will be used.
-____________: This iron atom in heme is bound to the fifth coordination site of the molecule.

Accepted Answer

A)  cooperative
B)  oxygen
C)  fMRI
D)  carbamate
E)  histidineF) hyperbolicG) myoglobinH) bicarbonate ionI) sickle-cell anemiaJ) protoporphyrinK) fetalL) carbonic acid

Question 20

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)   B and D

Exam 9: Hemoglobin: an Allosteric Protein

As the partial pressure of carbon dioxide increases, the affinity of oxygen binding to hemoglobin _____________.

Which of the following is correct concerning fetal hemoglobin?

Which of the following is not correct concerning myoglobin?

Use the following to answer questions 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.

The binding of 2,3-bisphosphoglycerate to hemoglobin _____________ (increases, decreases) its affinity of oxygen binding.

Which of the following describes the Bohr effect?

Use the following to answer questions 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.

2,3-bisphosphoglycerate binds only to the _____________ form of hemoglobin.

Hemoglobin binding of oxygen is best described as a:

What is the Bohr effect?

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

Describe the octahedral coordination sphere of the iron ion in hemoglobin and myoglobin.

Use the following to answer questions 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.

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

Use the following to answer questions 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.

Use the following to answer questions Choose the correct answer from the list below. Not all of the answers will be used. -____________: This method of studying hemoglobin monitors changes in magnetic fields during the binding of oxygen.

Use the concerted model to explain allosteric cooperative binding.

Why is it advantageous for hemoglobin to have allosteric properties?

Use the following to answer questions Choose the correct answer from the list below. Not all of the answers will be used. -____________: This iron atom in heme is bound to the fifth coordination site of the molecule.

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