Question

Identify the correct statement with reference to transport of respiratory gases by blood.

• A. Haemoglobin is necessary for transport of carbon dioxide and carbonic anhydrase for transport of oxygen
• B. Haemoglobin is necessary for transport of oxygen and carbonic anhydrase for transport of carbon dioxide
• C. Only oxygen is transported by blood
• D. Only carbon dioxide is transported by blood

Answer 1

The correct option is B Haemoglobin is necessary for transport of oxygen and carbonic anhydrase for transport of carbon dioxide

The reactions for both oxygen and carbon dioxide are coupled together and work in cooperation with each other. The main reason for this coupled effect is that both systems are influenced by hydrogen ions and equilibrium principles. At the lungs, the diffusion of oxygen into the blood triggers the reactions. The oxygen reacts with and attaches to hemoglobin. This oxygenation reaction with hemoglobin produces excess $H^{+}$ ions, which react with $HC{O}_3^{–}$ to produce $H_{2}C{O}_3$. The carbonic acid decomposes to $C{O}_2$, which diffuses out of the blood. So, the correct answer is 'haemoglobin is necessary for transport of oxygen and carbonic anhydrase for transport of carbon dioxide'.