Haemoglobin Synthesis & Catabolism
Let’s get to know what is haemoglobin!
Its molecule comprises 4 subunits, each containing an iron atom bound to a heme group.
What are the types of haemoglobin that is available in our body? Look!
Normal adult blood contains three types of haemoglobin as stated in the table below :
As what everybody knows, the main role of red blood cell is to carry O2 to the body tissue and eventually return CO2 from the tissue to the lungs. However, do you realised that in order to achieve these O2 and CO2 gaseous exchange, they require the specialized protein called as haemoglobin?
Little did we know that each red blood cells in our body contains approximately 640 million haemoglobin molecules. Amazing isn’t it? Each molecule of normal adult haemoglobin A (Hb A) consists of four polypeptide chains, where each with its own haem group. The molecular weight of Hb A is 68000 which is the largest amount of haemoglobin in blood cells. Normal adult also contain small quantities of two other hemoglobins ; Hb F and Hb A2 where both are made up from α chains, but with γ and δ chains, respectively, instead of β.
Have you even wonder how does the haemoglobin is synthesised? Here!
Haemoglobin synthesis occurs largely in the mitochondria by a series of biochemical reactions involving condensation of glycine and succinyl coenzyme A under the action of the key rate limiting enzyme δ-aminolaevulinic acid (ACA) synthase.
The figure above depict the formation of haemoglobin molecule with pyridoxal phosphate (vitamin B6) act as a coenzyme for the synthesise reaction. Ultimately, protophyrin combines with iron (Fe) where each molecule combines with globin chains each with its own heme group and eventually make up as a complete haemoglobin molecule.
The major switch from fetal to adult haemoglobin occurs 3-6 months after birth. Here are some videos on the synthesise overview from fetal to adult
Now lets proceed to the videos for better understanding! :)
REFERENCES LINK
1. https://www.docsity.com/en/haemoglobin-synthesis-and-catabolism-introduction-to-hematology-lecture-slides/221621/
2. https://allaboutblood.com/2011/08/30/haemoglobin-catabolism/
3. https://youtu.be/vhB0oNLYIqo