UCSB Respiratory System Hemoglobins Affinity for Oxygen Questions

Respiratory System: Hemoglobin’s Affinity for Oxygen Questions

1. The questions that follow pertain to the oxygen-hemoglobin dissociation curves below. For each
question, the middle line represents the normal oxygen-hemoglobin dissociation curve.
(a) Wow, you make it to the top of Mt Everest (30,000 ft)! On the basis of temperature, how would
the affinity of Hb for O2 change? In which direction would the normal curve shift (Left or
Right)?
(b) Still at the top of Mt Everest. . . On the basis of arterial CO2, how would the affinity of Hb for
O2 change? In which direction would the normal curve shift (Left or Right)?
(c) Back at sea level. . . You are seeing a patient (not at the top of Mt Everest) with emphysema
who has chronically elevated P CO2 How does your patient’s pH compare to normal? As a result
of this change in pH, how would the affinity of Hb for O2 change? In which direction would the
normal curve shift (Left or Right)?

(d) Cardiac and skeletal muscle contain a protein called myoglobin, which serves the same function as hemoglobin. In fact, the presence of myoglobin in the blood is sometimes used to confirm if a person is having a heart attack. Its main role is to serve as an O2 store for muscle in cases of severe oxygen deprivation. Which curve (Left/Right/Middle) would represent the expected affinity for oxygen of myoglobin compared to hemoglobin? Please defend your answer.

2. For the next 4 situations (a-d), please choose how the affinity of hemoglobin for oxygen would change
in each situation:
A. increase
B. decrease
(a) increased temperature
(b) increased pH
(c) increased P CO2
(d) increased 2, 3 ? DP G

3. Please draw a flow chart that shows the components of the reflex in which an increase in blood
P aCO2 leads to increased ventilation. Note which specific structure matches with each of the seven
general steps of a reflex arc.

4. Please write the chemical equation catalyzed by the enzyme carbonic anhydrase. Suppose the
concentration of H+ is increased by an outside force in a solution that had been at equilibrium. After
this occurs, how will the equation shift? What must happen to the CO2 concentration to reestablish
equilibrium after this disturbance? What must happen to the concentration of bicarbonate?