During exercise, lactic acid floods the blood, threatening to drop pH. Blood maintains pH near 7.4 due to the bicarbonate buffer system: H2CO3 / HCO3-. The reaction is: CO2 + H2O <=> H2CO3 <=> H+ + HCO3-.
When acid (H+) is added to blood, which species in the buffer system primarily neutralizes it?
- A
Water splits into H+ and OH- to neutralize
- B
CO2 oxidizes the H+
- C
H2CO3 splits to release more H+
- Dcheck_circle
HCO3- combines with H+ to form H2CO3
Explanation
HCO3- accepts the added proton to form H2CO3, which can then dissociate to CO2 and H2O exhaled by the lungs, restoring pH.