University:
Liberty University
Course:
BIOM 500 | Introduction to Biomedical Sciences
Academic year:

2024
Views:

51

Pages:

5
Author:

Sheha A.

Carbonic Acid (H₂CO₃) Bicarbonate (HCO₃⁻) Buffer System This system is based on the HCO₃⁻ which can act as a weak base and the H₂CO₃ which can act as a weak acid. If there is an excess of H⁺, the HCO₃⁻ can function as a weak base and remove the excess of H⁺ to form H₂CO₃. H⁺ + HCO₃⁻ → H₂CO₃ Then H₂CO₃ dissociates into water and CO₂ and the CO₂ is exhaled from the lungs. Carbonic Acid-Bicarbonate Buffer System If there is a shortage of H+, the H₂CO₃ can function as a weak acid and dissociate to provide H⁺ and HCO₃⁻. Because CO₂ and H₂O combine to form H₂CO₃, this buffer system cannot protect against pH changes due to respiratory problems in which there is an excess or shortage of CO₂. Phosphate Buffer This system acts via a mechanism similar to the carbonic acid-bicarbonate buffer system. Its components are the ions dihydrogen phosphate (H₂PO₄⁻) and monohydrogen phosphate (HPO₄²⁻). The H₂PO₄⁻ acts as a weak acid and is capable of buffering strong bases such as OH⁻ as follows: OH⁻ + H₂PO₄⁻ → H₂O + HPO₄²⁻