Sickle cell anaemia

• A mutation in the gene coding for the beta chain of haemoglobin causes sickle cell anaemia
• When the 4 polypeptide chains curl up in the RBC, they form a specific 3D shape
• If O2 levels fall, valine forms bonds with themselves that stick haemoglobin molecules together
• Haemoglobin molecules sticking together produces long chains of clumped haemoglobin molecules
• RBC is pulled out of its biconcave shape and produces a banana shape
• Sickled blood cell haemoglobin is less effective and has a smaller surface area, meaning less oxygen is carried
• Sickle cell is caused by a mutation in the gene that codes for the haemoglobin proteins
• Symptoms of sickle cell anaemia include fatigue, extreme pain and even strokes