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.
The name hemoglobin comes from heme and globin, since each subunit of hemoglobin is a globular protein with an embedded heme (or haem) group. Each heme group contains an iron atom, and this is responsible for the binding of oxygen.The presence of hemoglobin in blood increases the oxygen carrying ability of a litre of blood from 5 to 250 ml. Hemoglobin also plays a major role in the transport of carbon dioxide from the tissues back to the lungs.he iron atom in heme binds to the 4 nitrogen atoms in the centre of the porphyrin ring, but this leaves two free bonding sites for the iron, one on either side of the heme plane. The heme group is located in a crevice in the myoglobin molecule, surrounded by non-polar residues except for two polar histidines.