Factors Affecting Affinity of Haemoglobin for Oxygen
There are certain factors other than partial pressure that affects the Hb-O2 affinity. These factors determine whether the oxygen-hemoglobin dissociation curve will shift towards the right i.e. lower affinity of O2-Hb or the curve will shift towards the left i.e. higher affinity of O2-Hb. These factors are;
- pH: A decrease in pH as acidity increases results in the dissociation of O2 from Hb at any given pO2. The saturation becomes less and the curve shifts to the right, this is termed as Bohr Effect. Similarly, an increase in pH results in the shifting of the curve towards the left as the affinity of O2 for Hb increases.
- pCO2: As carbon can also bind with Hb, an increase in their concentration will result in a decrease in HB-O2 binding. This results in the shifting of the curve towards the right. Also when CO2 enters the blood it gets converted into carbonic acid, which due to the activity of an enzyme carbonic anhydrase present in RBC gets converted into bicarbonate and hydrogen ions. An increase in hydrogen ion concentration decreases the pH shifting the curve toward the right. Similarly, a decrease in the concentration of carbon dioxide in the blood will shift the curve toward the left.
- Temperature: An increase in temperature promotes the dissociation of O2 from Hb (one of the factors that promote the unloading of oxygen into tissues due to heat released by cellular metabolism) thus, shifting the curve towards the right as seen in fever. Lower body temperatures as in the case of hypothermia promote the binding of O2 with Hb and the curve shifts towards the left.
Factors Affecting Affinity of Haemoglobin for Oxygen
Also Read: Transport of Carbon Dioxide in Blood
Oxygen Transport in Blood
Oxygen is transported in the blood by binding to hemoglobin. Blood is responsible for the transportation of gases between the lungs and body tissues. Oxygen is transported bound to hemoglobin as it does not dissolve well in water present in plasma i.e. 97% of oxygen is transported with hemoglobin and the remaining 3% in plasma.
In this article, we will cover how oxygen is transported in blood, in detail.
Table of Content
- How is Oxygen Transported in Human Beings?
- Haemoglobin Protein in Blood
- Relationship Between Haemoglobin and Partial Pressure of Oxygen
- Factors Affecting Affinity of Haemoglobin for Oxygen
- Conclusion – Transport of Oxygen in Blood
- FAQs on How is Oxygen Transported in Human Beings?