AQA · GCSE · Biology
Course version: 8461 · Version from Sept 2018
Bacterial cells have been genetically engineered to produce useful…
Full specification wording
Genetic engineering: Bacterial cells have been genetically engineered to produce useful substances such as human insulin to treat diabetes.
Bacteria are useful hosts for genetic engineering because they reproduce rapidly and can be grown on a large scale.
Checked against the AQA 8461 specification (opens in a new tab) on .
- Point 3 of 13
- 3 key terms
Study notes
From the checked teaching notes for this specification point.
The idea
Bacteria are useful hosts for genetic engineering because they reproduce rapidly and can be grown on a large scale. To make human insulin, the human insulin gene is cut from human DNA using enzymes and inserted into a bacterial plasmid, which acts as a vector. The plasmid is put into a bacterium, and the modified bacterium is cultured. Because the human gene is now part of the bacterium's genetic material, the bacterium transcribes and translates it to make human insulin. The insulin is then extracted and purified for treating diabetes, where patients cannot produce enough of their own insulin. This process gives a reliable supply of human insulin rather than relying only on animal sources.
What earns the marks
- Bacteria can be genetically engineered to produce useful substances.
- Human insulin is an example of a useful substance made by genetically engineered bacteria.
- The human insulin gene is cut out and inserted into a bacterial plasmid used as a vector.
- The modified bacterium is cultured and expresses the human gene.
- The bacterium makes human insulin, which is extracted and purified.
- The insulin is used to treat diabetes, where the body does not produce enough insulin.
Common mistakes and how to put them right
Saying bacteria naturally make human insulin.
Put it right by stating that the human insulin gene must first be inserted into the bacterium.
Confusing the plasmid with the bacterial chromosome.
Put it right by describing the plasmid as a small circular DNA molecule used as a vector.
Thinking the bacterium makes insulin protein directly from DNA without RNA.
Put it right by including transcription and translation in the explanation.
Exam tips
- Use the terms plasmid, vector, culture and express when describing bacterial insulin production.
- Explain why bacteria are suitable hosts, for example rapid reproduction and large-scale growth.
- Link the product to its medical use by naming diabetes and the role of insulin in controlling blood glucose.
Try the lesson
The start of the Genetic engineering: Bacterial cells have been genetically engineered to produce useful substances such as human insulin to treat diabetes. lesson, made from checked teaching notes for this specification point.
Have a go first
Which substance is produced by genetically engineered bacteria to treat people who have diabetes?
Listen
Bacteria are useful hosts for genetic engineering because they reproduce rapidly and can be grown on a large scale. To make human insulin, the human insulin gene is cut from human DNA using enzymes and inserted into a bacterial plasmid, which acts as a vector. The plasmid is put into a bacterium, and the modified bacterium is cultured. Because the human gene is now part of the bacterium's genetic material, the bacterium transcribes and translates it to make human insulin. The insulin is then extracted and purified for treating diabetes, where patients cannot produce enough of their own insulin. This process gives a reliable supply of human insulin rather than relying only on animal sources. A strong answer earns marks for these points. Bacteria can be genetically engineered to produce useful substances. Human insulin is an example of a useful substance made by genetically engineered bacteria. The human insulin gene is cut out and inserted into a bacterial plasmid used as a vector. The modified bacterium is cultured and expresses the human gene. A common slip: Saying bacteria naturally make human insulin. Instead, stating that the human insulin gene must first be inserted into the bacterium. Exam tip: Use the terms plasmid, vector, culture and express when describing bacterial insulin production.
See it
Put it in order
Put these steps in the order they happen.
- 1. Bacterium transcribes and translates the human gene
- 2. Used to treat diabetes
- 3. Bacterium makes human insulin
- 4. Human insulin gene cut from human DNA using enzymes
- 5. Gene inserted into bacterial plasmid (vector)
- 6. Insulin extracted and purified
- 7. Plasmid put into a bacterium
- 8. Modified bacterium cultured
Key words
Say what each word means before you turn the card.
Bacterial hosts and plasmids
Try answering aloud or in your head before turning the card.
Treatment of diabetes
Try answering aloud or in your head before turning the card.
Medical applications of genetic engineering
Try answering aloud or in your head before turning the card.
See every definition
- Bacterial hosts and plasmids
- Bacteria are useful hosts because they reproduce rapidly and can be grown on a large scale, and a plasmid is a small circular DNA molecule used as a vector.
- Treatment of diabetes
- The extracted and purified insulin is used to treat diabetes, where patients cannot produce enough of their own insulin.
- Medical applications of genetic engineering
- Bacterial cells have been genetically engineered to produce useful substances such as human insulin, giving a reliable supply rather than relying only on animal sources.
Label the diagram
Some boxes have lost their names. Pick the right name for each number.
1Box 1
2Box 2
3Box 3
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