Essay On Haemoglobin

Haemoglobin is a globular protein which transports oxygen around the body. o Haemoglobin is able to carry oxygen, because of its prosthetic group; this is the helper of the protein. The prosthetic group here is ‘Heam’ this is known as Fe2+. Haemoglobin contains 4 Haem group, one for each polypeptide chain. o The Haem group provides a binding site for the oxygen molecule this is because oxygen exists as O2- ; oxygen is able to bind with the positively charged Fe2+, this allows haemoglobin to carry oxygen around the body.
• Haemoglobin consists of 4 polypeptide chains, 2 are alpha helix and 2 beta pleated sheets. Each polypeptide chain contains a Heam group which provides a binding site for oxygen.
• Haemoglobin is made of primary, secondary, tertiary and quaternary structures. o Primary structure of haemoglobin- This is the first level of protein structure. Haemoglobin is made up through the linking of amino acids which form polypeptide chains

Each polypeptide chain contains eight alpha helices. The alpha helices cause reactions between Globins to form stable structures. o Tertiary structure- this is where the Haem group of the polypeptide chains cause it to twist and fold to form the first 3D structure a structure for haemoglobin. o Quaternary structure- haemoglobin consists of 4 polypeptide chains 2 corresponding alpha chains and 2 matching beta chains. The bonding of these polypeptide bonds form the quaternary structure.• The bonding which occurs in this is: o Hydrogen bonding- this bonding occurs between the hydrogen and oxygen or nitrogen between amino acids opposite each other. This bond occurs because the oxygen is slightly negative and the nitrogen/hydrogen is slightly positive so there is an attraction between them when they come close together. This is a fairly weak bond however it forms a vital part in helping the structure stay strong and in the right