Question

Oxygen haemoglobin dissociation curve will shift to right on decrease of

• A. Acidity
• B. Carbon dioxide concentration
• C. Both A and B
• D. pH

Answer 1

The correct option is D pH

A decrease in pH (increase in $H^{+}$ ion concentration) shifts the standard curve to the right, while an increase shifts it to the left. This occurs because at greater $H^{+}$ ion concentration. So, with increased acidity, the haemoglobin binds less $O_2$ for a given $P{O}_2$ (and more $H^{+}$). This is known as the Bohr effect.