Question

Define oxygen dissociation curve. Can you suggest any reason for its sigmoidal pattern?

Answer 1

The oxygen dissociation curve is a graph showing the percentage saturation of oxyhaemoglobin at various partial pressures of oxygen.



The curve shows the equilibrium of oxyhaemoglobin and haemoglobin at various partial pressures.



In the lungs, the partial pressure of oxygen is high. Hence, haemoglobin binds to oxygen and forms oxyhaemoglobin.







Tissues have a low oxygen concentration. Therefore, at the tissues, oxyhaemoglobin releases oxygen to form haemoglobin.



The sigmoid shape of the dissociation curve is because of the co-operative binding of oxygen to haemoglobin. As the first oxygen molecule binds to haemoglobin, it increases the affinity for the second molecule of oxygen to bind. Subsequently, haemoglobin attracts more oxygen.Hence Haemoglobin is a positively co-operative protein.

Hope this will help you......✌

Answer 2

Answer:

The oxygen dissociation curve deals with amount of hemoglobin saturated with oxygen by presenting oxygen concentration in the x axis and percent saturation in the y axis

Explanation:

Hemoglobin binds with oxygen to form oxyhemoglobin.one hemoglobin molecule has 4 oxygen binding site.

        The oxy hemoglobin dissociation curve is sigmoidal in nature because homotropic binding of oxygen with hemoglobin.it means the binding of one molecule of 02 to a subunit of hemoglobin facilitates the oxygen  binding affinity of the rest other subunits.