What happens to the O2 dissociation curve in the presence of lower pH, according to the Bohr Effect?

The correct answer is that the O2 dissociation curve shifts right in the presence of lower pH due to the Bohr Effect. This physiological phenomenon occurs because a decrease in pH (which corresponds to an increase in hydrogen ion concentration) enhances the release of oxygen from hemoglobin.

When the pH drops, the hemoglobin molecule's structure changes, making it less bind to oxygen. This facilitates oxygen unloading in tissues that are metabolically active and producing carbon dioxide, which also contributes to the lower pH by forming carbonic acid. The rightward shift in the dissociation curve indicates that at a given partial pressure of oxygen, hemoglobin has a lower oxygen saturation, which is essential for meeting the oxygen demands of tissues under these conditions.

Understanding this shift is crucial for recognizing how the body adapts to varying metabolic demands and acid-base balance, particularly during exercise or other states of increased metabolism.