Question

Haemoglobin is a Fe containing protein responsible for oxygen transport in the blood. The curves given below indicate the percentage saturation of haemoglobin by O₂ as a function of partial pressure of O₂.

Which of the following statement/s is /are correct for the given curves? 

I. In presence of CO₂, higher O₂ P is needed for a given percentage saturation 

II. In presence of CO₂, lower O₂ P is needed for a given percentage saturation 

III. The maximum percentage saturation is not affected by the presence of CO₂ 

IV. In the absence of CO₂, maximum saturation of haemoglobin occurs at lower P_O2

(A) I and IV 

(B) II and IV 

(C) I, III and IV 

(D) II and III

Answer 1

Correct answer is (C) I, III and IV

According to given information graph I would be in presence of CO₂ and II would be in absence of CO₂. 

Now we can conclude from graph that 

(i) In presence of CO₂ higher O₂ P in needed for a given percentage saturation. 

(ii) The maximum percentage saturation is not affected by presence of CO₂. 

(ii) In the absence of CO₂, maximum saturation of haemoglobin occurs at lower O_2.