Chapter 9 Quiz
B
A fetus does not breathe inside the womb, and so it must obtain oxygen a different way. What property of hemoglobin allows a fetus to recieve the oxygeN it needs to develop? A. Fetal hemoglobin has a lower affinity for oxygen than adult hemoglobin. B. Fetal hemoglobin has a higher affinity for oxygen than adult hemoglobin. C. The partial pressure of oxygen in fetal hemoglobin is always higher than that of its mother. D. Fetal hemoglobin is composed of four subunits while adult hemoglobin is composed of two.
D
Allosteric effects that occur in hemoglobin A. are important for maintaining Fe in the Fe2+ state. B. minimize oxygen delivery to the tissues. C. optimize oxygen delivery to the tissues. D. can also be observed in myglobin.
D
Bilirubin is a byproduct of heme catabolism, and is excreted in the bile and stool. Bilirubin is likely derived from processes in what cell type? A. Epithelial cells B. Adipocytes C. Enterocytes D. Red blood cells
D
Hemoglobin is the protein responsible for the transport of oxygen throughout the bloodstream. The saturation of hemoglobin can be graphed based on the pressure of oxygen. As the pressure of oxygen increases, the saturation of hemoglobin with oxygen will increase in a sigmoidal fashion. This oxygen dissociation curve can be shifted depending on the external conditions in the blood. Which of the following factors will not decrease the dissociation curve between oxygen and hemoglobin? A. A decrease in pH B. An increase in carbon dioxide pressure C. An increase in temperature D. The partial pressure of oxygen
D
Identify the pH for each oxygen dissociation curve in the graph. Answers are listed in respect to curve 1, curve 2, and curve 3. A. 7.2, 7.4, 7.6 B. 7.4, 7.2, 7.6 C. 7.6, 7.2, 7.4 D. 7.6, 7.4, 7.2
A
If an individual's blood has a slightly lower pH than normal, this means that oxygen affinity to hemoglobin __________. A. decreases B. remains the same because only temperature can affect affinity C. remains the same because only carbon dioxide levels can affect affinity increases D. remains the same because only oxygen levels can affect affinity
A
In deoxyhemoglobin (Hb), the Fe (II) is 5-coordinated to A. four nitrogens of heme and to the proximal His of Hb. B. four nitrogens of heme and to a water molecule. C. four nitrogens of heme and to an O2 molecule. D. two nitrogens of heme and to three His residues in Hb.
B
In sickle cell anemia, the basis of the malfunction of the hemoglobin molecule is: A. incorrect secondary structure. B. substitution of a single amino acid. C. faulty binding of the heme groups. D. reduced affinity for oxygen. E. insufficient iron in the diet.
C
Myoglobin is a similar carrier molecule to hemoglobin, but it only has one site of oxygen binding instead of four. Which characteristic of hemoglobin is most likely not shared by myoglobin? A. Ability to reversibly bind oxygen B. Level of solubility C. Cooperativity D. Iron-binding capacity
B
Number of heme molecule(s) in myoglobin, number of subunit(s) in myoglobin, and number of oxygen molecule(s) carried by myoglobin are _________ respectively A. 2, 3, 1 B. 1, 1, 1 C. 2, 2, 1 D. 1, 4, 2
B
Select the scenarios which, according to the Bohr effect, result in hemoglobin's release of bound oxygen. I. Oxygen levels in the blood increase. II. The pH of blood decreases. III. Carbon dioxide levels in the blood increase. IV. The concentration of hydrogen ions in the blood decreases. A. I, II, III B. II and III C. II, III, and IV D. Only one of the above answers are correct
D
The following small molecules affect hemoglobin as indicated: A. Decreased [H+] and [N3-] decrease Hb affinity for O2. B. Increased [H+] and [C1-] increase Hb affinity for O2. C. Increased [C0] and [C1-] increase Hb affinity for O2. D. Increased [H+] and [C1-] decrease Hb affinity for O2.
A
The shape of the oxygen dissociation curve of myoglobin is A. hyperbola B. parbolia C. sigmoid D. linear
C
Under which of the following conditions will hemoglobin bind less oxygen? A. The pH increases from 7.0 to 7.2 B. The oxygen pressure increases from 500 mm to 1000 mm C. The concentration of carbon dioxide increases D. The BPG is removed
A
What drives the loading of oxygen onto hemoglobin molecules in the lungs? A. the high partial pressure of oxygen in the lungs B. the low partial pressure of oxygen in the lungs C. the high partial pressure of carbon dioxide in the lungs D. the low partial pressure of carbon dioxide in the lungs
E
What is the primary function of myoglobin? A. Oxygen carrier B. Oxygen reservoir C. Anti-oxidant D. None of the above E. A and B
D
Which factors contribute to the Bohr Effect? A. Low pH, low CO2 B. Low pH, high CO2, low temperature C. High pH, low CO2 D. Low pH, high CO2
D
Which of the following gases can be bound by hemoglobin? A. Carbon dioxide B. Carbon monoxide C. Oxygen D. All of the above answers are correct
A
Which of the following is most likely to decrease oxygen's affinity to hemoglobin in the bloodstream? A. Low pH B. Low levels of carbon dioxide C. High pH D. Low temperature
D
Which of the following scenarios will cause the oxygen-hemoglobin dissociation curve to shift to the left? A. Decreased pH B. Exercise C. Increased 2,3-bisphosphoglycerate D. Hyperventilation
C
Which of the following statements are true? I. Myoglobin has a higher affinity for oxygen than hemoglobin II. The binding of oxygen by myoglobin is not cooperative III. Myoglobin binds oxygen in muscle cells A. I and III B. II and III C. I, II, and III D. III only
