Why do we breathe in oxygen?

1 Answer
Aug 2, 2017

Oxygen is required for metabolism and processes that produce energy in the body.

Explanation:

Oxygen is inhaled because it is required for oxidative processes at the cellular level to help with cell growth and repair and to produce energy for the body's processes.

Oxygen combines with glucose, the primary energy source, to produce energy in the mitochondria, the cell's powerhouse.

This site offers a more detailed explanation:
Why Do We Inhale Oxygen And Exhale Carbon Dioxide?