Fetal Hgb differs from adult Hgb in that it is active to bind oxgen with greater affinity allowing the fetus to obtain oxygen from the mother's blood stream.
What accounts for the increase affinity?
Answers
Answer:
Explanation:
the presence of hemoglobin F in the fetus allows a stronger binding to oxygen than maternal hemoglobin (see section Why hemoglobin F has high oxygen affinity). Secondly, the mother's bloodstream is richer in oxygen that the fetus', so oxygen naturally flows towards the fetal circulation by diffusion.
Answer:
Fetal hemoglobin, or foetal haemoglobin (also hemoglobin F, HbF, or α2γ2) is the main oxygen carrier protein in the human fetus. Hemoglobin F is found in fetal red blood cells, and is involved in transporting oxygen from the mother's bloodstream to organs and tissues in the fetus. It is produced at around 6 weeks of pregnancy and the levels remain high after birth until the baby is roughly 2–4 months old. Hemoglobin F has a different composition from the adult forms of hemoglobin, which allows it to bind (or attach to) oxygen more strongly. This way, the developing fetus is able to retrieve oxygen from the mother's bloodstream, which occurs through the placenta found in the mother's uterus.
In the newborn, levels of hemoglobin F gradually decrease and reach adult levels (less than 1% of total hemoglobin) usually within 1 year of life, as adult forms of hemoglobin begin to be produced. Diseases such as beta thalassemias, which affect components of the adult hemoglobin, can delay this process, and cause hemoglobin F levels to be higher than normal. In sickle cell anemia, increasing the production of hemoglobin F has been used as a treatment to relieve some of the symptoms.