What is the effect of pCO2 on oxygen transport?

The partial pressure of CO₂ (pCO₂) affects oxygen transport through the Bohr effect. When pCO₂ increases (like in active tissues), blood becomes more acidic (lower pH). This reduces hemoglobin’s affinity for O₂, making it release oxygen more easily where it’s needed most.

In the lungs, where pCO₂ is lower, the pH rises, and hemoglobin binds oxygen more tightly—helping oxygen loading. So, high pCO₂ promotes oxygen unloading, while low pCO₂ favors loading.