Diabetes

• Type 1 diabetes = unable to produce insulin
• Type 2 diabetes = patients cannot effectively use insulin and control their blood sugar levels. This is either because the person's beta cells do not produce enough insulin or because the body cells do not respond properly to insulin. This is often because the glycoprotein insulin receptor does not work properly.
• Originally, insulin was obtained from the pancreas of cows and pigs. However, this process was difficult and expensive. The insulin extracted could also cause allergic reactions as it differed slightly from human insulin.
• Now we use genetically modified bacteria to produce human insulin. This is less likely to cause allergic reactions, produced in much higher quantities, cheaper and there are no ethical or religious concerns over using animals.