To survive, humans need to breathe in oxygen gas. Oxygen is essential for cellular respiration, a process that allows the body to produce energy by breaking down carbohydrates to form ATP (adenosine triphosphate), which powers various metabolic functions in the body. Oxygen makes up about 21% of the air we breathe, and it is produced naturally by photosynthetic organisms like green plants and algae.
The air is a mixture of gases, primarily nitrogen (about 78%) and oxygen (about 21%), with small amounts of other gases like carbon dioxide and argon. Nitrogen acts mostly as a diluent to keep the lungs functioning properly but is not metabolically used by the body. The critical gas for survival is oxygen because it supports the biological processes that maintain life.
In summary, oxygen is the vital gas humans need to inhale continuously to survive.
