alpha2 beta 2; little contact between alpha1 and alpha 2, or beta 1 and beta 2
describe iron in deoxy-hemoglobin
about 0.4 outside heme plane; rion with 5 ligands is too large to fit exactly in plane of heme; O2 binding reduces size of iron and it can move into plane
what is the function of 2,3-BPG?
lowers Hb affinity for oxygen (promotes oxygen release); more oxygen is needed to make energy; modulate amount of oxygen from hemeglobin to myoglobin