Question

Haldane effect plays a more important role in promoting carbon dioxide transport than that of the Bohr's effect in promoting oxygen transport because

• A. Oxyhemoglobin is a stronger acid which donates hydrogen ion (H+) which in turn displace carbon dioxide from blood
• B. Carbaminohaemoglobin is a stronger acid which splits into hydrogen ion (H+) and bicarbonate ($HC{O}_3^{-}$)
• C. Carbon dioxide reacts with water to form carbonic acid that lowers the pH in tissue
• D. Carbon dioxide is less soluble in venous blood than in arterial blood.

Answer 1

The correct option is A Oxyhemoglobin is a stronger acid which donates hydrogen ion (H+) which in turn displace carbon dioxide from blood

The degree of oxygenation of blood markedly affects the amount of $C{O}_2$ transported in the blood. The lower the P$O_2$ and the haemoglobin saturation with $O_2$, the more the $C{O}_2$ that can be carried in the blood. This phenomenon is called the Haldane effect. It depicts the greater ability of reduced haemoglobin to form carbaminohemoglobin and to buffer H+ by combining with it.

In the pulmonary circulation, uptake of $O_2$ facilitates the release of $C{O}_2$. As haemoglobin becomes saturated with $O_2$, the hydrogen ions released combine with $HC{O}_3^{-}$, helping to unload $C{O}_2$ from the pulmonary blood. The Haldane effect is quantitatively more important in promoting $C{O}_2$ transport than the Bohr effect in promoting $O_2$ transport. It results from the simple fact that a combination of $O_2$ with haemoglobin causes the haemoglobin (oxyhemoglobin) to become a stronger acid. This, in turn, displaces $C{O}_2$ from the blood.

So the correct answer is 'Oxyhemoglobin is a stronger acid which donates hydrogen ion (H+) which in turn displace carbon dioxide from blood'.