BICH 409 EXAM 2 UPDATED ACTUAL QUESTIONS AND
CORRECT ANSWERS
Question:
1. when a glutamic acid residue is shifted from the surface
of a protein into a hydrophobic, nonpolar pocket in the
interior of the protein, the pKa of the glutamic acid
___________.
a. decreases
b. increases
c. remains unchanged
Answer:
b. increases
Question:
2. when a glutamic acid residue is brought into close
proximity to an aspartate residue the pKa of the glutamic
acid residue __________.
a. decreases
b. remains unchanged
c. increases
Answer:
c. increases
Question:
3. if the pH decreases from 7.4 to 7.3, the p50 of
hemoglobin would
a. decrease
b. cannot be determined
c. increase
d. remain unchanged
e. none of these
Answer:
c. increase
, Question:
4. which of the following statements about the oxidation
state of iron is not true?
a. the iron center of the heme in Methemoglobin is in the
Fe3+ state.
b. a water molecule binds to the heme bound iron when
the iron is in the ferric state.
c. the binding of oxygen in hemoglobin or myoglobin,
oxidizes the heme iron from the Fe2+ to the Fe3+ state.
d. all of these statements are not true.
e. oxygen binds to the heme bound iron when the iron is
in the ferrous state.
Answer:
c. the binding of oxygen in hemoglobin or myoglobin, oxidizes the heme iron
from the Fe2+ to the Fe3+ state.
Question:
5. when the pCO2 increases from 10 to 40 torr, the oxygen
affinity of hemoglobin __________.
a. reamins unchanged
b. increases
c. decreases
Answer:
c. decreases
Question:
6. a monomeric oxygen-binding protein has a fractional
saturation of 0.8 when pO2 = 8 torr. What is the value of
p50 for this protein and what is the value of the hill
coefficient n?
Answer:
p50 = 2
n=1
Question:
7. 2,3 Biphosphoglycerate:
a. increases the oxygen binding affinity of hemoglobin.
b. is bound to hemoglobin primarily through electrostatic
interactions.
c. bind to the distal histidine of hemoglobin.
d. binds to hemoglobin and stabilizes the R-state.
e. increases the oxygen binding affinity of myoglobin.
Answer:
b. is bound to hemoglobin primarily through electrostatic interactions.
CORRECT ANSWERS
Question:
1. when a glutamic acid residue is shifted from the surface
of a protein into a hydrophobic, nonpolar pocket in the
interior of the protein, the pKa of the glutamic acid
___________.
a. decreases
b. increases
c. remains unchanged
Answer:
b. increases
Question:
2. when a glutamic acid residue is brought into close
proximity to an aspartate residue the pKa of the glutamic
acid residue __________.
a. decreases
b. remains unchanged
c. increases
Answer:
c. increases
Question:
3. if the pH decreases from 7.4 to 7.3, the p50 of
hemoglobin would
a. decrease
b. cannot be determined
c. increase
d. remain unchanged
e. none of these
Answer:
c. increase
, Question:
4. which of the following statements about the oxidation
state of iron is not true?
a. the iron center of the heme in Methemoglobin is in the
Fe3+ state.
b. a water molecule binds to the heme bound iron when
the iron is in the ferric state.
c. the binding of oxygen in hemoglobin or myoglobin,
oxidizes the heme iron from the Fe2+ to the Fe3+ state.
d. all of these statements are not true.
e. oxygen binds to the heme bound iron when the iron is
in the ferrous state.
Answer:
c. the binding of oxygen in hemoglobin or myoglobin, oxidizes the heme iron
from the Fe2+ to the Fe3+ state.
Question:
5. when the pCO2 increases from 10 to 40 torr, the oxygen
affinity of hemoglobin __________.
a. reamins unchanged
b. increases
c. decreases
Answer:
c. decreases
Question:
6. a monomeric oxygen-binding protein has a fractional
saturation of 0.8 when pO2 = 8 torr. What is the value of
p50 for this protein and what is the value of the hill
coefficient n?
Answer:
p50 = 2
n=1
Question:
7. 2,3 Biphosphoglycerate:
a. increases the oxygen binding affinity of hemoglobin.
b. is bound to hemoglobin primarily through electrostatic
interactions.
c. bind to the distal histidine of hemoglobin.
d. binds to hemoglobin and stabilizes the R-state.
e. increases the oxygen binding affinity of myoglobin.
Answer:
b. is bound to hemoglobin primarily through electrostatic interactions.
