Which gas is essential for human respiration?

Oxygen is essential for human respiration because it is the gas that our cells use to produce energy. The process of cellular respiration involves taking in oxygen and using it to help convert glucose (a type of sugar) into adenosine triphosphate (ATP), which is the energy currency of the cell. This chemical reaction also produces carbon dioxide as a byproduct, which we then exhale.

In the lungs, oxygen from the air we breathe enters the bloodstream and is carried to cells throughout the body. Without a sufficient supply of oxygen, cells cannot perform their necessary functions, leading to the failure of organs and ultimately endangering life. This is why maintaining adequate oxygen levels in the environment is crucial for health and survival.

Other gases, like carbon dioxide, nitrogen, and hydrogen, play different roles in the body or the environment, but they do not serve as the primary gas required for the process of aerobic respiration that powers human cells.