Final answer:
The effect of carbon dioxide on oxygen binding by hemoglobin is determined by the Haldane effect and the Bohr effect. When hemoglobin is saturated with oxygen, it has a reduced ability to bind carbon dioxide. The pH of the blood also affects the oxygen binding capacity of hemoglobin, with lower pH promoting oxygen release.
Step-by-step explanation:
The effect of carbon dioxide on oxygen binding by hemoglobin (Hb) is based on two principles: the Haldane effect and the Bohr effect.
Haldane effect:
When hemoglobin is saturated with oxygen, it has a reduced ability to bind carbon dioxide. However, when oxygen is not bound to hemoglobin and the partial pressure of oxygen is low, hemoglobin readily binds to carbon dioxide. In other words, oxygenation of hemoglobin reduces its ability to bind carbon dioxide.
Bohr effect:
The pH of the blood also affects the oxygen binding capacity of hemoglobin. A lower pH, which is more acidic, promotes the release of oxygen from hemoglobin. This is important because the presence of carbon dioxide in the blood leads to the production of hydrogen ions, reducing the blood pH. As a result, hemoglobin releases oxygen more readily in the presence of carbon dioxide.