AQA · GCSE · Biology
Course version: 8461 · Version from Sept 2018
A genetically modified bacterium produces human insulin. When harvested and…
Full specification wording
Role of biotechnology: A genetically modified bacterium produces human insulin. When harvested and purified this is used to treat people with diabetes.
Human insulin can be produced using a genetically modified bacterium.
Checked against the AQA 8461 specification (opens in a new tab) on .
- Point 5 of 6
Study notes
From the checked teaching notes for this specification point.
The idea
Human insulin can be produced using a genetically modified bacterium. The human insulin gene is inserted into a bacterial plasmid, and the bacterium is grown in a fermenter. Because the gene is expressed, the bacteria make human insulin. The bacteria are then harvested and the insulin is purified so that it can be used safely. People with diabetes may not produce enough insulin or may not respond properly to it, so insulin injections help control blood glucose concentration. Compared with extracting insulin from animal pancreases, this method can produce large quantities of human insulin that is identical to the human hormone, reducing the risk of immune reactions. The skill is to link genetic modification, fermentation, purification and medical treatment.
What earns the marks
- The human insulin gene is inserted into a bacterium, making it genetically modified.
- The modified bacterium is cultured so that it expresses the human gene and produces insulin.
- The bacteria are harvested and the insulin is purified before use.
- The purified human insulin is used to treat people with diabetes.
- Using human insulin avoids reliance on animal pancreases and can be produced in large quantities.
Common mistakes and how to put them right
Thinking the bacterium naturally makes human insulin.
Put it right: It only does so after the human insulin gene has been inserted.
Confusing the bacterium with the insulin.
Put it right: The bacterium is the producer, and insulin is the product harvested and purified from it.
Believing insulin cures diabetes.
Put it right: Insulin treatment manages blood glucose concentration but does not cure the condition.
Exam tips
- State the role of the plasmid as a vector for carrying the human insulin gene into the bacterium.
- Explain that purification is needed before the insulin can be used medically.
- Link insulin treatment to controlling blood glucose concentration in people with diabetes.
Try the lesson
The start of the Role of biotechnology: A genetically modified bacterium produces human insulin. When harvested and purified this is used to treat people with diabetes. lesson, made from checked teaching notes for this specification point.
Have a go first
A genetically modified bacterium is grown in a fermenter to produce human insulin. What is the human insulin used for?
Listen
Human insulin can be produced using a genetically modified bacterium. The human insulin gene is inserted into a bacterial plasmid, and the bacterium is grown in a fermenter. Because the gene is expressed, the bacteria make human insulin. The bacteria are then harvested and the insulin is purified so that it can be used safely. People with diabetes may not produce enough insulin or may not respond properly to it, so insulin injections help control blood glucose concentration. Compared with extracting insulin from animal pancreases, this method can produce large quantities of human insulin that is identical to the human hormone, reducing the risk of immune reactions. The skill is to link genetic modification, fermentation, purification and medical treatment. A strong answer earns marks for these points. The human insulin gene is inserted into a bacterium, making it genetically modified. The modified bacterium is cultured so that it expresses the human gene and produces insulin. The bacteria are harvested and the insulin is purified before use. The purified human insulin is used to treat people with diabetes. A common slip: Thinking the bacterium naturally makes human insulin. Instead, it only does so after the human insulin gene has been inserted. Exam tip: State the role of the plasmid as a vector for carrying the human insulin gene into the bacterium.
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