CO2 + H2O ⇔ H2CO3 ⇔ H+ + HCO3- The equаtiоn аbоve represents the bicаrbоnate/carbonic acid buffering system within the blood. This system allows humans to maintain homeostasis (balance) of pH within the blood. Without this system working properly the blood would become too acidic or too basic. Question: When a person experiences kidney failure, their body produces and excretes urine containing large amounts of HCO3-. Use your knowledge of buffers to determine how the loss of HCO3- affects the pH of the blood plasma.