Imagine a blood substitute in which the binding of O2 to its carrier protein is not altered by pH. How would the use of such a blood substitute affect breathing? Describe/discuss/explain briefly.

Answer 1

Hi Basma. A good question!

Imagine a blood substitute in which the binding of O2 to its carrier protein is not altered by pH. How would the use of such a blood substitute affect breathing? Describe/discuss/explain briefly.

This is the key phrase:

the binding of O2 to its carrier protein is not altered by pH

In your body, the pH of your blood determines whether or not your hemoglobin is going to pick up O₂ or release it. Near your lungs, the CO₂ concentration is lower, so the pH rises and your hemoglobin picks up O₂. In your tissues, the CO₂ concentration is higher, so the pH drops and causes your hemoglobin to release O₂ into your tissues, It is only because your hemoglobin is pH sensitive that the oxygen can be picked up in your lungs, transported in the bloodstream and finally released into your tissues so that cellular respiration can occur.

Think about it: If the blood substitute is not affected by pH, then it will neither pick nor release O₂. You could breathe all you want (pumping air in and out of your lungs), but you would still suffocate as your cells died from a lack of oxygen.