Explain Oxygen Dissociation Curve

While different partial pressures of oxygen are  plotted against the amount of  oxyhaemoglobin created or  dissociated, the sigmoid  curve  is acquired,  as  displayed in  Figure which  is termed as  oxygen dissociation  curve.

The oxygen dissociation curve is a graph which depicts the percent saturation of haemoglobin at various partial pressures of oxygen. The aim of an oxygen dissociation curve is to show the equilibrium of oxyhaemoglobin and nonbonded haemoglobin at several partial pressures. At high partial pressures of oxygen, generally in the lungs, haemoglobin binds to oxygen to form oxyhaemoglobin. While the blood is fully saturated, all the erythrocytes are in the form of oxyhaemoglobin. Since the erythrocytes travel to tissues deprived of oxygen, the partial pressure of oxygen will decrease. Subsequently, the oxyhaemoglobin releases the oxygen to form haemoglobin.