What primary function do bicarbonate ions serve in the body?

Bicarbonate ions play a critical role in maintaining pH balance in the blood, which is essential for normal physiological function. They act as a buffer in the bicarbonate buffer system, which helps to regulate the acidity and alkalinity of the blood. When the concentration of hydrogen ions in the blood rises, resulting in a decrease in pH (leading to acidosis), bicarbonate ions can react with these hydrogen ions to neutralize their effect, thus raising the pH back to a more normal range. Conversely, if the blood becomes too alkaline, bicarbonate can dissociate to release hydrogen ions, helping to lower the pH.

This buffering capacity is vital because enzymes and other biochemical processes in the body function optimally at a specific pH range. Therefore, the role of bicarbonate ions is fundamental to maintaining homeostasis within the body’s internal environment, particularly in the respiratory and metabolic processes that can affect blood pH levels.