Question

During breathing we inhale oxygen. Why does our cells need oxygen? What happens with that oxygen?

Answer 1

We know that breathing is a physical process of inhaling oxygen and exhaling carbon dioxide. Breathing is actually a part of respiration, which is a biochemical process in which food is broken down in cells to release energy. Thus the oxygen that we take in required for the process of respiration involving breakdown of food to release energy. We say that food is oxidised in respiration. Also carbon dioxide and water along with energy are released in this oxidation of food.