Question

Although both food and oxygen are necessary for life,man can live without food for a number of days,but he dies without oxygen with few minutes.why?

Answer 1

Because Oxygen Is necessary for Breathing and our Blood Needs fresh oxygen to supply it to all parts of our body..As we eat, The amount of excess energy produced is stored in the form of "Glycogen".When our body needs energy this extra glycogen is converted in glucose again and therefore we can survive for some days without Food. Hope it helps :)

Answer 2

Because, food is needed for energy, and after eating food, it is conserved, and lasts long.

However oxygen is needed for heart to pump blood, brain to function etc. And it doesn't last long.

Therefore oxygen should be quickly replenished to live than food.