3 Answers. In Great Britain today, the role of the queen is completely ceremonial. She (and whoever comes after her as monarch) has absolutely no actual power. In political science terms, she is the head of state for Great Britain but is not head of government.
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.
So, the curve has an s-shape because, at lower PO2s, oxygen binds to hemoglobin at a high rate, and this slows down as hemoglobin become more saturated. At PO2s above 60 the curve is relatively flat, meaning that the oxygen content of the blood will not change much with subsequent increases in PO2. Shift to the left: The curve shifts to the left when hemoglobin has an increased affinity for oxygen, and has an easier time making the bond with oxygen. 2  Higher SpO2 for a given PO2. 3  Hemoglobin is more likely to cling to O2 and not let go (activity is minimal). 4  Think Cold.