Question

Choose the best answer for the below situation and explain your answer

East Lansing, MI Vail, CO

ambient pO2 159 mmHg 95mmHg

tracheal pO2 149 86

alveolar pO2 105 50

arterial pO2 100 45

Information on oxygen pressures are provided above for Michigan and Colorado.You leave East Lansing for a holiday skiing trip.Two days after arriving at Vail, the best prediction for [2,3-diphosphoglycerate] and P50 for your body is:

(The symbols, ↑, ↓, and ↔ represent increase, decrease, and remain the same, relative to Michigan.)

[2,3-diphosphoglycerate] P50(mmHg)

A) ↑ ↑

B) ↑ ↓

C) ↔ ↔

D) ↓ ↓

E) ↓ ↑

Answer 1

The best answer for this question is “ option B”.

Living at high altitude for some days activated the formation of 2,3 diphosphoglycerate (DPG) in RBC of blood. DPG binds with haemoglobin beta chain and displaced bound oxygen. Normally, moving to higher altitudes will resulted in shifting of haemoglobin oxygen dissociation curve to the right because of increased levels of RBC DPG .

As in high altitude, temperature is decreases, so P50 will decrease as decrease in temperature , result in the weakening of bond between haemoglobin and oxygen.

Hence, option “B” is correct.