Question

Which of the following conditions is/are favorable for oxyhaemoglobin formation in alveoli?
i) High partial pressure of oxygen, low partial pressure of carbon dioxide
ii) Low partial pressure of oxygen, high partial pressure of carbon dioxide
iii) Low pH, low temperature
iv) High pH, high temperature

• A. Only i is correct
• B. Both i and ii are correct
• C. Both i and iii are correct
• D. Both iii and iv are correct

Answer 1

The correct option is C Both i and iii are correct

Haemoglobin is an oxygen-carrying red coloured pigment. It is located in the erythrocyte (red blood cells). Haemoglobin binds with oxygen in a reversible manner to form oxyhaemoglobin. This binding is primarily dependent on the partial pressure of oxygen. Other facts that affect this binding are partial pressure of carbon dioxide, temperature, and hydrogen ion concentration. In alveoli (air sacs in the lungs), oxyhaemoglobin formation is favoured when there is high partial pressure of oxygen, low partial pressure of carbon dioxide, low pH, and low temperature. It is in the tissues where there is low partial pressure of oxygen, high partial pressure of carbon dioxide, high pH, and high temperature that the dissociation of oxyhaemoglobin is favoured.