Question

Refer to the given figure and answer the question.
Select the factors that are responsible for left shift of the oxygen dissociation curve:

I. Increase in $pC{O}_2$
II. Decrease in temperature
III. Increase in ${\mathrm{pO}}_2$
IV. Decrease in $H^{+}$ concentration
V. Increase in 2,3 DPG

• A. I, II and III
• B. I, II, III and IV
• C. I and III
• D. II, III and IV

Answer 1

The correct option is D II, III and IV

The given graph shows the oxygen – haemoglobin dissociation curve. The relationship between the ${\mathrm{pO}}_2$ and the percent saturation of haemoglobin when represented on a graph is termed as oxygen – haemoglobin dissociation curve. It is S-shaped because of the behaviour of the Hb in different ${\mathrm{pO}}_2$ . The factors that causes left shift on the graph are as follows:
I. Decrease in $pC{O}_2$
II. Decrease in temperature
III. Increase in ${\mathrm{pO}}_2$
IV. Decrease in $H^{+}$ concentration
V. Decrease in 2,3 DPG (2,3 Diphosphoglyceric acid)