Question

Exposure to carbon monoxide (e.g., coal gas) is extremely dangerous and can kill a person because -

• A. Carboxyhaemoglobin reduces the ability of blood to transport oxygen by rupturing a vast majority of erythrocytes.
• B. The compound carboxyhemoglobin is formed with haemoglobin, which gradually clots the blood resulting in circulatory failure.
• C. Carboxyhaemoglobin greatly modifies the structure of haemoglobin, thus making it lose its affinity for oxygen.
• D. Carboxyhaemoglobin is formed which decreses binding affinity of oxygen

Answer 1

The correct option is D Carboxyhaemoglobin is formed which decreses binding affinity of oxygen

The combination of carbon monoxide and haemoglobin forms a stable compound called carboxyhaemoglobin (HbCO). The affinity of haemoglobin is much higher for carbon monoxide than for oxygen and thus, even minute quantities of carbon monoxide in the blood can make haemoglobin unavailable for oxygen transport.