Explanation:
In tissues CO2 enter in red blood cells and converted into HCO-3 with the release of H+ ion;reaction is catalysed by carbonic anhydrase enzyme
Released H+ ions reduces pH of cells and facilitate dissociation of oxygen from hemoglobin
This is favored by T state which occurs in tissues
Hemoglobin mainly exists in two conformations: T state and R state
T state consists of deoxygenated hemoglobin,less affinity for oxygen and is favored by tissues
R state consists of oxygenated hemoglobin,high affinity for oxygen and is favored by lungs
T state is dominant conformation of deoxy hemoglobin and stabilized by ionic interactions whereas oxygen binding stabilizes R state
Here in case of crocodile,underwater there is increased binding of HC0-3 to the T state because there is less affinity for oxygen underwater hence T state will be dominant