Which effect promotes oxygen unloading due to increased CO2 levels?

The Bohr effect describes the physiological phenomenon where an increase in carbon dioxide (CO2) concentration and a corresponding decrease in pH promote the release of oxygen from hemoglobin. This effect is crucial during activities that increase cellular respiration and CO2 production, such as exercise. When CO2 levels rise, it leads to the formation of carbonic acid, which lowers the pH of blood. Hemoglobin's affinity for oxygen decreases in this acidic environment, facilitating oxygen unloading in tissues that need it most. This mechanism ensures that areas with high metabolic activity receive more oxygen, thereby enhancing overall tissue function.

The other effects mentioned, such as the allosteric and carbamino effect, have different implications regarding oxygen transport but do not primarily focus on the role of increased CO2 levels in promoting oxygen unloading like the Bohr effect does. The chronic obstructive effect is not a recognized physiological mechanism in the context of gas exchange.