Question

1. hemoglobin extracted from red blood cells has a much greater affinity for oxygen than hemoglobin within a red blood cell. How do you account for this difference in affinity?

Answer 1

Haemoglobin is extracted out from adult red blood cells. Adult red blood cells have more affinity for oxygen than red blood cells of foetus. Reason being, mother's blood full fill the additional oxygen requirement of foetus.

Inside red blood cells haemoglobin act as carrier of oxygen. It has main function of binding and releasing of oxygen as per requirement of various cells in physiological action.

Once extracted out from red blood cells, haemoglobin have only binding action. No releasing function is needed now. Hence affinity for binding oxygen seems to be at larger scale at this extracted stage.

Myoglobin is analog of haemoglobin which has more affinity for oxygen than haemoglobin.