Gasses: We Breathe In and Breathe Out

The air which we breathe in and breathe out is not pure oxygen or carbon dioxide respectively. As we all knew that our body and the cells inside it requires more oxygen to respire and to perform its regular functions and our environment does not provide us with an exclusive supply of oxygen. In a similar way, while breathing out, we do exclusively give out carbon dioxide. Let’s know more about the composition of gases we breathe.

Composition of Inhaled and Exhaled Air

Gases we Breathe In

We all are aware that our atmosphere is a mixture of gases and its contains 78% nitrogen, 21% oxygen, 1% argon, 0.04% carbon dioxide, 0.5% water vapour. When we breathe in, we inhale the same mixture of gases contained in the atmosphere as our nose cannot filter out the oxygen from other gases.

Composition of Air

During the respiration process, the total composition of the air that we breathe in also depends on our surrounding environment. Let say, the underwater divers inhale air containing more oxygen or helium. Similarly, the space suits worn by astronaut supplies pure oxygen for them to breathe in space.

Gases we Breathe Out

Stand in front of a mirror and breath out. You will see a film of moisture appearing on the mirror surface. Have you ever wondered where do these water droplets come? It is the same air that we inhale. As mentioned earlier the air which we breathe in contains 0.05% water vapor. Therefore, the film of moisture formed on the mirror surface is because of the water vapor content in the air.

Composition of Gases: Exhaled Air

When we exhale, the composition of the air remains almost same as the air we inhale, only the percentage of carbon dioxide and oxygen changes. The amount of inhaled air contains 21% of oxygen and 0.04% of carbon dioxide, while the air we breathe out contains 16.4% of oxygen and 4.4% of carbon dioxide. This is because our cells use oxygen from the inhaled air to release energy and give out carbon dioxide as a byproduct.

Hence, this was a brief introduction to the composition of gases during respiration. Stay tuned with Byju’s to learn more about Gases


Practise This Question

Which organ is damaged by smoking?