Question

Carbon monoxide, emitted by automobiles, prevents the transport of oxygen in the body due to

• A. Combining with oxygen to form carbon dioxide
• B. Destruction of haemoglobin
• C. Preventing reaction between oxygen and haemoglobin
• D. Forming stable compound with haemoglobin

Answer 1

The correct option is D Forming stable compound with haemoglobin

Mechanism of action of Carbon monoxide

CO has more affinity for haemoglobin than oxygen.

1. It forms a stable compound with haemoglobin called carboxyhemoglobin.
2. It occupies the oxygen binding sites of haemoglobin and therefore prevents the transportation of oxygen-rich blood across the body.

Carbon monoxide has greater affinity for haemoglobin than oxygen. Also binding of CO at one haemoglobin site alters its affinity towards oxygen such that oxygen unloading in peripheral tissues gets affected.

Final answer

(D) Forming stable compound with haemoglobin