Haemoglobin
Created | Updated Feb 18, 2007
Haemoglobin is the pigment found in red blood cells, which carries oxygen. It is a protein. It is globular in shape and it is made up of four polypeptide chains, two of these chains are the same and are called alpha chains and make up one identical pair and the other two are also the same and make up what are called beta chains, these four chains pack closely together and there hydrophobic R groups point inwards towards the centre of the molecule and there hydrophilic ones point outwards, the beta chains have a tertiary structure similar to that of myoglobin.
Each polypeptide chain has a haem group. A haem group is called a prosthetic group because it is an important permanent part of a protein but it is not made up of amino acids. Each Haem group is made up of one iron ion Fe2+ and one oxygen molecule, O2 can bind with each iron ion, this means that a complete haemoglobin molecule can carry four oxygen molecules (eight oxygen atoms) at a time. Haem groups are responsible for the colour of the blood so when it is carrying oxygen it is red and is known as oxyhaemoglobin and if not the colour s purple, this is why the blood in ve3ins is purple because it id taking deoxygenated blood back to the heart. Red blood cells are adapted to there job as they have no nucleus which increases there surface area and therefore allows them to carry more oxygen.
Sickle cell anaemia is a disease, which is due to a fault in the haemoglobin molecule; this fault is that one amino acid is wrong on the beta chain, the correct acid is glutamic acid, which is polar, but in the faulty molecule the acid is valine, which is non-polar. Having this non-polar R group on the outside of the molecule makes the molecule less soluble and this can have disastrous effects for those who suffer the disease. Some of the symptoms are:
Family history of sickle cell anaemia, fatigue, breathlessness, rapid heart rate, delayed growth and puberty, susceptibility to infections ulcers on the lower legs (in adolescents and adults) jaundice, attacks of abdominal pain, weakness, joint pain, fever, vomiting, bloody (hematuria) urination, excessive thirst, excessive penis pain, priapism, chest pain and decreased fertility.
Each polypeptide chain has a haem group. A haem group is called a prosthetic group because it is an important permanent part of a protein but it is not made up of amino acids. Each Haem group is made up of one iron ion Fe2+ and one oxygen molecule, O2 can bind with each iron ion, this means that a complete haemoglobin molecule can carry four oxygen molecules (eight oxygen atoms) at a time. Haem groups are responsible for the colour of the blood so when it is carrying oxygen it is red and is known as oxyhaemoglobin and if not the colour s purple, this is why the blood in ve3ins is purple because it id taking deoxygenated blood back to the heart. Red blood cells are adapted to there job as they have no nucleus which increases there surface area and therefore allows them to carry more oxygen.
Sickle cell anaemia is a disease, which is due to a fault in the haemoglobin molecule; this fault is that one amino acid is wrong on the beta chain, the correct acid is glutamic acid, which is polar, but in the faulty molecule the acid is valine, which is non-polar. Having this non-polar R group on the outside of the molecule makes the molecule less soluble and this can have disastrous effects for those who suffer the disease. Some of the symptoms are:
Family history of sickle cell anaemia, fatigue, breathlessness, rapid heart rate, delayed growth and puberty, susceptibility to infections ulcers on the lower legs (in adolescents and adults) jaundice, attacks of abdominal pain, weakness, joint pain, fever, vomiting, bloody (hematuria) urination, excessive thirst, excessive penis pain, priapism, chest pain and decreased fertility.
