A decrease in bicarbonate will do what to the pH?

A decrease in bicarbonate will do what to the pH?

• A. Increase It
• B. Decrease It
• C. Make It Neutral
• D. No Change

Answer: (B)

Bicarbonate is the main extracellular base in the buffering system, neutralizing hydrogen ions to form carbonic acid, which becomes CO2 and water. When bicarbonate decreases, there’s less base to neutralize H+, so more free hydrogen ions remain, causing the pH to fall (the solution becomes more acidic). In the Henderson-Hasselbalch relation, with CO2 constant, lowering bicarbonate lowers the pH. The body can compensate by changing ventilation to adjust CO2, but the immediate effect of less bicarbonate is a decrease in pH.

Bicarbonate is the main extracellular base in the buffering system, neutralizing hydrogen ions to form carbonic acid, which becomes CO2 and water. When bicarbonate decreases, there’s less base to neutralize H+, so more free hydrogen ions remain, causing the pH to fall (the solution becomes more acidic). In the Henderson-Hasselbalch relation, with CO2 constant, lowering bicarbonate lowers the pH. The body can compensate by changing ventilation to adjust CO2, but the immediate effect of less bicarbonate is a decrease in pH.