Binding of O2 to hemoglobin reduces its affinity for CO2 by

Haldane effectBecause deoxyhemoglobin binds more H+ than oxyhemoglobin does and forms carbamino compounds more readily, binding of O2 to hemoglobin reduces its affinity for CO2The decrease in O2 affinity of hemoglobin when the pH of blood falls is called the Bohr effect and is closely related to the fact that deoxygenated hemoglobin (deoxyhemoglobin) binds H+ more actively than does oxygenated hemoglobin (oxyhemoglobin)CHLORIDE SHIFT: Because the rise in the HCO3- content of red cells is much greater than that in plasma as the blood passes through the capillaries, about 70% of the HCO3- formed in the red cells enters the plasma. The excess HCO3- leaves the red cells in exchange for Cl- Ref: 23rd Edition of Ganong's Review of Medical Physiology page no: 612