2. HbF is the predominan hemoglobin of embrions. It has two y-and two a- subunits (a_(2)/2) HbF does not bind 2,3-BFG well What is the affinity of oxygen binding for HbF in compare with HbA? For answer: 1) Explain the function of HbA and the role of 2,3-BFG in the regulation of O_(2) 2) Draw the oxygen-binding curves of Hb and HbF. 3) Mark the biological significance of the difference in O_(2) affinity for HbA and HbF.

1) HbA (adult hemoglobin) is the predominant form of hemoglobin in adults and has two alpha (α) and two beta (β) subunits (α2β2). HbA has a higher affinity for oxygen compared to HbF (fetal hemoglobin). The 2,3-BPG (2,3-bisphosphoglycerate) is a molecule that binds to hemoglobin and reduces its affinity for oxygen. This is important in the regulation of oxygen binding, as it allows hemoglobin to release oxygen where it is needed, such as in tissues with high oxygen demand.<br /><br />2) The oxygen-binding curves of HbA and HbF can be represented as follows:<br /><br />[Insert image of oxygen-binding curves for HbA and HbF]<br /><br />3) The difference in oxygen affinity between HbA and HbF is biologically significant because it allows for efficient oxygen transfer from the mother to the fetus during pregnancy. HbF has a higher affinity for oxygen, which allows it to bind oxygen more readily in the fetal circulation. This ensures that the fetus receives an adequate supply of oxygen for its development. On the other hand, HbA has a lower affinity for oxygen, which allows it to release oxygen more readily in the adult tissues where it is needed. This difference in oxygen affinity between HbA and HbF is crucial for maintaining proper oxygen levels in both the fetus and the adult.