Home » Frequently asked Questions on Health » What is the difference between adult and fetal haemoglobin?

What is the difference between adult and fetal haemoglobin?

Q: What is the difference between adult and fetal haemoglobin?

A:Haemoglobin (Hb), the oxygen carrying protein present in our red blood cells, is made up of an iron containing Haeme molecule surrounded by a protein called Globin. Each Hb molecule contains two pairs of globin chains. Different Hbs are found in humans during the embryonic, fetal and adult life and they differ from each other in the type of globin chain they possess. Except in the first few weeks of embryo formation, one globin chain pair is always alpha while the second pair is termed non-alpha - (beta , gamma , delta). It is the combination of 2 alpha-chains with different non-alpha chains that gives rise to different types of Hbs. The production of these different globin chains is governed by distinct genes called a, b, g, d, etc. An adult normally has the following types of haemoglobins (Hb) present in blood: Hb A – made up of 2 alpha & 2 beta globin chains: 95% of total Hb A2 – made up of 2 alpha & 2 delta globin chains: 3% of total Hb F – made up of 2 alpha & 2 gamma globin chains: 1-2% of total In order to deliver oxygen to the tissues, haemoglobin must be able both to bind oxygen and to release oxygen. Hb A and Hb F differ (besides their structure), in their oxygen affinity i.e. the tightness with which they bind to oxygen. This is primarily due to the different function they perform in adult and fetal life. The developing fetus does not breathe the way we do by drawing air into its lungs (where there is plenty of oxygen). Instead, it draws its oxygen from the mother's blood (where the oxygen content is low). Hb F is equipped to do this as it binds to oxygen with greater affinity than does Hb A thus extracting more oxygen for the developing fetus, thus facilitating oxygen transfer from the mother to the developing baby. The levels of fetal Hb rapidly fall after birth as now the lungs are functional and Hb A is better suited for oxygen delivery and this occurs by the switching off of the g-gene.

RELATED FAQ

................... Advertisement ...................

   

FAQ

ASK OUR EXPERTS

Using 0 of 1024 Possible characters
Choose Topic

Latest stories

World Pharmacists Day 2017: A Brief History of Pharmacy And Pharmacists In India

Mon, 25 Sep 2017 20:00:16 IST
September 25th is observed as the World Pharmacists Day every year. Here's a brief history of how the profession of pharmacy and pharmacists came into being in India.

Once World’s Heaviest Woman, Eman Ahmed Dies In Abu Dhabi

Mon, 25 Sep 2017 18:30:17 IST
Eman Ahmed Abd El Aty, once known as the world's heaviest woman, died at the Burjee Hospital in Abu Dhabi on Monday. She hailed from Egypt and weighed approximately 500 kg.

Sexual Harassment By Coworkers Causes More Severe Depression

Mon, 25 Sep 2017 17:30:18 IST
Employees who are sexually harassed by work colleagues may develop more severe symptoms of depression than those who experience harassment by clients or customers, a study has found.

Smartphone Apps To Cure Depression?

Mon, 25 Sep 2017 16:30:18 IST
From connecting us to the world, giving us important information from all the corners to entertaining us, smartphones today pretty much sort our lives out. But what if we told you that your handy little device can also help treat serious mental problems as such depression?

Multi-Gene Test May Better Predict Who Will Suffer From Dementia

Mon, 25 Sep 2017 15:30:38 IST
A new test that combines the effects of over two dozen gene mutations - which individually lead to only a small increased risk of Alzheimer's disease - can better predict who will suffer from dementia or cognitive decline, scientists say.