70 75 of CO2 in the body is converted into carbonic acid (H2CO3), which can quickly turn into bicarbonate.

The name may also mean an ester of carbonic acid, an organic compound containing the carbonate group C( O)(O )2.

Sodium, chloride, and phosphate ions are essential for life, as are some inorganic molecules such as carbonic acid, nitrogen, carbon dioxide, water, and oxygen.

This is the case for , which is reduced by photosynthesis of plants, and which, after dissolving in the oceans, reacts to form carbonic acid and bicarbonate and carbonate ions (see ocean acidification).