Answer: The bicarbonate buffer system is a chemical system that helps to regulate the pH of the blood and other bodily fluids. It consists of a mixture of bicarbonate ions (HCO3-) and dissolved carbon dioxide (CO2) in a solution, along with a weak acid and its conjugate base.
When there is an excess of acid (such as when there is too much carbon dioxide in the blood), the bicarbonate ions can react with the excess hydrogen ions (H+) to form carbonic acid (H2CO3), which can then be broken down into water and carbon dioxide by the enzyme carbonic anhydrase. This process helps to decrease the acidity of the blood.
On the other hand, when there is too little acid in the blood, the carbonic acid can be broken down into carbon dioxide and water, releasing hydrogen ions and increasing the acidity of the blood. This process helps to maintain the normal pH range of the blood, which is approximately 7.35 to 7.45.