what is the shape of the oxygen hemoglobin dissociation curve
Overview. 1  Oxygen-hemoglobin dissociation curve sigmoidal shape is characteristic of positive cooperativity binding of 1 O2 molecule to 1 subunit of deoxyhemoglobin increases affinity for O2 in adjacent subunits. P50 is PO2 at which hemoglobin is 50% saturated â P50 â â hemoglobin affinity for O2 50% saturation achieved at higher-than-normal P50.