Question

Using pH as an example, explain the Bohr Effect and how it increases O2 delivery to actively metabolizing tissue.

Answer 1

The Bohr effect is a physiological phenomenon that refers to the shift in oxygen dissociation caused by changes in the pH of the environment.
This effect explains how hydrogen ions and carbon dioxide affect the affinity of oxygen in Hemoglobin.
When pH is lower than it normally (normal physiological pH is 7.4), then the hemoglobin does not bind oxygen . Which means the lower the pH, the more Hydrogen ions, the higher the carbon dioxide level and the less affinity Hemoglobin has for oxygen; the higher the pH, the lower the Hydrogen ion concentration, the lower the carbon dioxide level, and the greater affinity hemoglobin has for oxygen
It also caused by changes in concentration of carbon dioxide it will reacts with water to form carbonic acid, an increase in carbon dioxide results in a decrease in blood pH.
When pH of blood decreases it promotes dissociation of oxygen from hemoglobin,it does not have as much affinity to keep the oxygen binded to the heme group. Tand allows surrounding tissue to obtain oxygen to meet their demand. The lower pH will cause hemoglobin to deliver more oxygen to actively metabolising tissues.
The Bohr effect enables the body to adapt to changing conditions and makes it possible to supply extra oxygen to tissues that need it the most. For example, when muscles are undergoing vigorous activity, they require large amounts of oxygen to conduct cellular respiration, which generates CO2 (bicarbonate and hydrogen ions) as byproducts. These waste products lower the pH of the blood, which increases oxygen delivery to the active muscles.
Decrease in carbon dioxide leads to increase in pH, which results in hemoglobin taking up more oxygen. Once hemoglobin binds to oxygen in lungs due to high concentration of oxygen, the Bohr effect facilitates oxygen release in the tissues, particularly those tissues which require oxygen.