Understanding:
• The Bohr shift explains the increased release of oxygen by haemoglobin in respiring tissues
The oxyhaemoglobin dissociation curve demonstrates the saturation of haemoglobin by oxygen under normal conditions
- pH changes alter the affinity of haemoglobin for oxygen and hence alters the uptake and release of O2 by haemoglobin
Carbon dioxide lowers the pH of the blood (by forming carbonic acid), which causes haemoglobin to release its oxygen
- This is known as the Bohr effect – a decrease in pH shifts the oxygen dissociation curve to the right
Cells with increased metabolism (i.e. respiring tissues) release greater amounts of carbon dioxide (product of cell respiration)
- Hence haemoglobin is promoted to release its oxygen at the regions of greatest need (oxygen is an input of cell respiration)
The Bohr Shift
