Fetal hemoglobin has a pair of gamma-globin molecules in place of the typical beta-globins of adult hemoglobin
Fetal hemoglobin (Hemoglobin F), Alkali-resistant hemoglobin, HBF (or Hb F), is the major hemoglobin component in the bloodstream of the fetus. After birth, it decreases rapidly until only traces are found in normal.
Greater than 2% of total hemoglobin is abnormal.
FalseAdult hemoglobin has less affinity for oxygen than fetal hemogloblin. That is why, as an adult female's blood passes BY the placenta, the oxygen diffusses into the fetal blood. Likewise, adult blood, having explelled the carbon dioxide during exhalation, has less concentration of carbon-dioxide than the fetal blood, so it diffuses out of fetal blood into the adult blood. That way, the fetus doesn't need respiration as an oxygen source, nor as a way to rid of waste and carbon dioxide.
Hemoglobin F, also known as fetal hemoglobin is not found in adult blood.
adult Hb ha 2-alpha+2delta structure while fetal has 2-alpha+2-gamma. and this renders it more interactive towards oxygen, hence fetal hb has more affinity for oxygen as compared to adult hemoglobin.
Fetal haemoglobin has a higher affinity for oxygen, so is less able to dissociate than maternal haemoglobin within body tissues and cells.
The change is important because there is no need for the effieciency of a fetal haemoglobin in a healthy adult.
Reference values vary from laboratory to laboratory but are generally found within the following ranges: six months to adult: up to 2% of the total hemoglobin, newborn to six months: up to 75% of the total hemoglobin.
Fetal hemoglobin, or foetal haemoglobin, is the main oxygen transport protein in the fetus during the last seven months of development in the uterus and in the newborn until roughly 6 months old.
Sickle cell anemia is a genetic problem so you are born with it. Initially babies make a different kind of hemoglobin (fetal hemoglobin) and so do not have problems right away. Usually by 6-12 month s of age they are making the sickle hemoglobin and can start to have problems.
nonidentical genes that produce different versions of globins during development.
Fetuses possess a different type of haemoglobin to their mothers - HbF rather than HbA. The purpose of this is to allow the developing infant to 'steal' oxygen from it's mother. This normally has no adverse effects on the pregnant woman other than perhaps feeling a little breathless after mild exercise. HbF has what is described as a 'greater affinity for oxygen' and a 'lower affinity for carbon dioxide' to HbA. This allows the fetus to load oxygen and unload carbon dioxide with more ease than the mother, and so ensuring survival.