Question

Carbon monoxide can kill a person because of it’s extremely high affinity for
A) Haemoglobin
B) Phytochrome
C) Cytochrome
D) None of these

Answer 1

Hint:Carbon monoxide is a gas which is colorless, odorless, flammable and is also slightly less dense than air. Carbon monoxide exposure causes adverse effects to the heart and the central nervous system of animals.

Complete answer:
Carbon monoxide poisoning is a very fatal kind of air poisoning that affects a wide range of animals. Carbon monoxide is found to bind to haemoglobin at the same place here oxygen binds, but the binding affinity of carbon monoxide is much greater than oxygen. The complex formed when carbon monoxide binds to haemoglobin is known as carboxyhemoglobin and it reduces the capacity of haemoglobin to deliver oxygen to different body tissues. Low concentrations of carbon monoxide such as 667ppm can cause 50% of the haemoglobin to get converted into carboxyhemoglobin. Carbon monoxide poisoning gives rise to different conditions, few of which are headache, vomiting, nausea, fatigue and weakness. It can also cause neurological anomalies such as confusion, visual disturbance, disorientation and seizures and ultimately causes the death of the person. Carbon monoxide is also capable of binding to other molecules of the body such as myoglobin and cytochrome. But these bindings happen to a lesser extent and do not have such adverse effects.

Hence the correct answer is option (A) Haemoglobin.

Note: Though carbon monoxide has adverse effects above a certain concentration, minute amounts of it are used as signaling molecules. It plays roles such as neurotransmitter or blood vessel relaxant in the body.