Question

Carbon monoxide, emitted by automobiles, prevents transport of oxygen in 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

The haemoglobin is the respiratory pigment in the red blood cells. It binds with the oxygen due to the iron moiety present in the heme group. However, the inhalation f the carbon monoxide results in the competition between the CO and the oxygen and because the CO has a higher affinity to the haemoglobin, it binds to form a stable compound called carboxyhaemoglobin. This compound also binds to the oxygen but it does not release the oxygen at the level of the tissues. So, despite the presence of the oxygen, the tissues do not get it. This is called carbon monoxide poisoning.

Hence, the correct answer is 'Forming stable compound with haemoglobin'.