Explain how hemoglobin’s oxygen binding affinity changes with pH and CO2 (Bohr effect) and the physiological significance.

Explain how hemoglobin’s oxygen binding affinity changes with pH and CO2 (Bohr effect) and the physiological significance.

• A. Hemoglobin affinity for oxygen increases with lower pH and higher CO2.
• B. Decreased pH or increased CO2 lowers Hb affinity for O2, shifting curve to the right, promoting unloading; higher pH and lower CO2 shift left, promoting loading.
• C. Hemoglobin affinity is not affected by pH or CO2.
• D. Oxygen binding is enhanced when CO2 is high.

Answer: (B)