The key difference between Bohr effect and Root effect is that in the Bohr effect, only the affinity to oxygen is reduced, whereas, in the Root effect, both affinity and carrying capacity for oxygen are reduced.
The Bohr effect and Root effect are comparable phenomena that are discussed in this article. These terms are related to the hemoglobin-oxygen combinations.
CONTENTS
1. Overview and Key Difference
2. What is Bohr Effect
3. What is Root Effect
4. Bohr Effect vs Root Effect in Tabular Form
5. Summary – Bohr Effect vs Root Effect
What is Bohr Effect
Bohr effect is the shift in the oxygen dissociation curve caused by changes in the concentration of carbon dioxide or the pH of the environment. This phenomenon was first described by the Danish physiologist Christian Bohr in 1904. Carbon dioxide reacts with water to form carbonic acid. Therefore, an increase in CO2 can result in a decrease in blood pH. This, in turn, makes hemoglobin proteins release their load of oxygen. A decrease in carbon dioxide can provoke an increase in pH that can result in hemoglobin picking up more oxygen.
The Bohr effect increases the efficiency of oxygen transportation through the blood. After the binding of hemoglobin to oxygen in the lungs due to the high oxygen concentrations, the Bohr effect can facilitate the release in the tissues, mostly the tissues that are in most need of oxygen. When the metabolic rate of tissue is increased, the carbon dioxide forming bicarbonate and protons also increase.
Figure 01: Dissociation Curves from Bohr’s Experiments
This reaction usually proceeds slowly. But the enzyme carbonic anhydrase drastically speeds up the conversion of bicarbonate and protons. This, in turn, causes the pH of the blood to decrease. This also promotes the dissociation of oxygen from hemoglobin and allows the surrounding tissues to obtain enough oxygen to meet the demands.
What is Root Effect?
Root effect indicates that an increased proton or carbon dioxide concentration lowers the hemoglobin’s affinity and carrying capacity for oxygen. This effect occurs as a physiological phenomenon in fish hemoglobin.
The hemoglobin showing the Root effect shows a loss of cooperativity at low pH. This, in turn, results in the Hb-O2 dissociation curve, which is shifted downward and not just to the right. Hemoglobin shows the Root effect, which does not become fully oxygenated even at oxygen tensions up to 20kPa.
In addition, this effect allows the bladder to go against a high oxygen gradient, and it is noted in the choroid rate, where the network of blood vessels can carry oxygen to the retina. When there is no Root effect, retia will result in the diffusion of some oxygen directly coming from the arterial blood to reach the venous blood. This makes such systems less effective for the concentration of oxygen. It has been hypothesized that loss affinity is useful in providing more oxygen to red muscles during acidotic stress.
What is the Difference Between Bohr Effect and Root Effect?
Bohr effect and Root effect are important phenomena. The key difference between Bohr effect and Root effect is that in the Bohr effect, only the affinity to oxygen is reduced, whereas, in the Root effect, both affinity and carrying capacity for oxygen are reduced.
The following table summarizes the difference between Bohr effect and Root effect.
Summary – Bohr Effect vs Root Effect
The Bohr effect is the shift in the oxygen dissociation curve caused by changes in the concentration of carbon dioxide or the pH of the environment. Root effect indicates that an increased proton or carbon dioxide concentration lowers the hemoglobin’s affinity and carrying capacity for oxygen. The key difference between Bohr effect and Root effect is that in the Bohr effect, only the affinity to oxygen is reduced, whereas, in the Root effect, both affinity and carrying capacity for oxygen are reduced.
Reference:
1. “Bohr Effect.” An Overview | ScienceDirect Topics.
Image Courtesy:
1. “Bohr effect” By Christian Bohr – Bohr, C., Hasselbalch, K., and Krogh, A. (1904) Ueber einen in biologischer Beziehung wichtigen Einfluss, den die Kohlensäurespannung des Blutes auf dessen Sauerstoffbindung übt. Skandinavisches Archiv Für Physiologie, 16(2): 402-412. doi:10.1111/j.1748-1716.1904.tb01382.x. (Public Domain) via Commons Wikimedia