Question

6. The formation of bicarbonate creates an excess of H in blood cells. Examine Figure 5-16 and describe the effect of the binding of oxygen when pH decreases. How does this help in the transport of oxygen in tissues? (This is the so-called Bohr effect.)

Answer 1

In the tissues the pH is 7.2.That is, less basic as compared to that of lungs.

From the above diagram, we see that O2 binding is better at a higher pH. That is, in more basic conditions.

Therefore, O2 binds more efficiently in the lungs than in the tissues.

Also, from the diagram it is clear that if haemoglobin has to bind oxygen at a lower pH value then the pressure of O2 must be even higher.

However, in the tissues, the pressure of O2 is much lower than that in the lungs.

Therefore, O2 binds to the haemoglobin efficiently in the lungs which is carried to the tissues where it is released.

Therefore, O2 binding is pH dependent and dependent on the pressure of O2.

Higher the pH and higher the pressure of O2, better will be the O2 binging to the haemoglobin.

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