why hbf has high affinity for oxygen?
Affinity of HbF for oxygen. The high affinity of HbF for O2 favors the taking up of oxygen in the placenta. This high affinity of HbF for O2 is explained by its low affinity for 2,3 DPG (diphosphoglycerate), an organic phosphate present in the erythrocytes that normally competes with O2 for the binding to Hb.