Question

Which life process helps in release of energy? and which gas is inhaled into our body during breathing?

Answer 1

Respiration includes the exchange of gases as well as burning of food. Animals have a well defined respiratory system for respiration. In the process of respiration, glucose is broken down to extract energy. It is a redox reaction which can take place with or without oxygen and takes place in mitochondria of the cell and releases energy in the form of ATP.

Breathing is the physical process of inhaling oxygen and exhaling carbon dioxide. Breathing is somewhat like an "external" respiration.
So the major gas in the inhaled air is oxygen needed for respiration.