John N. answered • 06/27/19
Experienced AP Biology/Anatomy/Physiology Tutor
The Bohr Shift is a change in hemoglobin’s affinity for oxygen due to an increase in the concentration of carbon dioxide in the blood or an increase in the acidity of the blood. It is important because as carbon dioxide levels increase, the affinity of oxygen by hemoglobin at the same partial pressure of oxygen is lower, which means that oxygen is more easily released to body tissues which would be in a greater need of oxygen. Similarly, if blood acidity is increased, it is due to having a higher amount of carbon dioxide released in the blood, which then reacts with water to form carbonic acid. Carbonic acid dissociates into hydrogen ions (H+) and bicarbonate ions (HCO3-). Obviously this would increase the acidity of the blood. In addition, and more importantly, during strenuous activity, muscles resort to anaerobic respiration, creating lactic acid, which significantly lowers the pH of the blood. As oxygen is more easily released into the cells, cells are able to return to aerobic respiration, creating pyruvate rather than lactate, which results in a decrease in the acidity of the blood and a return to normal.
