What is meant by: the H+ ion attach proteins to side chains of amino acids in oxy-HB in Bohr Effect?
When the pH decreases, this means that the H+ ions concentration increases. Hemoglobin contributes to buffer this acidosis by carrying some of those H ions (protons). This occurs by protonations of some of its amino acids. Then when it goes to the lung, these protons (H+ ions) will be combined by bicarbonates there to form carbonic acid by the action of an enzyme called carbonic anhydrase. Carbonic acid will dissociate spontaneously into CO2 and H2O. CO2 will be exhaled in the expiration.
