People breathe to bring oxygen into their bodies and to expel carbon dioxide, which is a waste product of cellular respiration. Oxygen is essential for the body's cells to function and produce energy through a process called cellular respiration.
When we inhale, air containing oxygen enters our lungs. Oxygen from the air diffuses into the bloodstream through the walls of the lungs' tiny air sacs, called alveoli. The oxygen-rich blood is then pumped by the heart to various parts of the body, where it is used by cells for energy production.
At the cellular level, oxygen is used in the process of cellular respiration to break down glucose molecules and produce adenosine triphosphate (ATP), which is the primary energy currency of cells. As a result of cellular respiration, carbon dioxide is produced as a waste product, which is transported back to the lungs through the bloodstream.
When we exhale, carbon dioxide-rich air is expelled from the lungs, removing this waste product from the body.
In summary, breathing is necessary to oxygenate the body's cells and remove carbon dioxide, ensuring the proper functioning of bodily systems and the maintenance of cellular processes.
