Molecular Classification
Other (inorganic anion), Electrolyte component, Buffer system component
Other Names
Hydrogen carbonate, Hydrogencarbonate, Carbonic acid ion, Hydroxidodioxidocarbonate(1−), CHO₃⁻
Disease Roles
Other (disturbances in bicarbonate levels are associated with metabolic acidosis, metabolic alkalosis, respiratory acidosis, and respiratory alkalosis)

Bicarbonate ion Overview

The **bicarbonate ion** (HCO₃⁻), also known as **hydrogen carbonate**, is a polyatomic anion that plays a central role in maintaining physiological pH balance through its function as part of the body's primary buffer system. It forms via the reversible dissociation of carbonic acid and serves as both a conjugate base to carbonic acid and a conjugate acid to carbonate. In biological systems, it helps regulate blood pH by neutralizing excess acids or bases, facilitates CO₂ transport from tissues to lungs for exhalation, and participates in cellular volume regulation. While essential for homeostasis, it is not considered a therapeutic target such as an enzyme or receptor but rather an important physiological molecule whose concentration serves as a clinical biomarker for various metabolic conditions.

Mechanism of Action

Biological Functions

Acid-base (pH) buffering in blood and tissues
CO₂ transport in the bloodstream
Cellular pH regulation
Volume regulation in cells

Disease Associations

Other (disturbances in bicarbonate levels are associated with metabolic acidosis, metabolic alkalosis, respiratory acidosis, and respiratory alkalosis)

Safety Considerations

No safety concerns listed

Associated Biomarkers

Biomarker
Blood bicarbonate level (used to assess acid-base status and diagnose metabolic or respiratory disorders)