What you need to know
- 8.17Drugs produced using genetically modifiedHaving DNA that has been changed by genetic engineering, often by adding a gene from another organism. plants, animals and microorganisms.
No doses, no prescribing, and no instruction to culture a pathogen. Building the recombinant molecule is 8C 1. Risks of releasing GMOs are 8C 4.
By the end, you should be able to…
- Describe a microorganism making a human protein from an inserted geneA sequence of DNA bases that codes for a polypeptide or a functional RNA..
- State one way a genetically modified plant or animal can be the producerAn organism, usually a plant, that makes its own organic molecules by photosynthesis. Producers form the first trophic level..
- Keep the host, the gene and the drug as three different things.
Build your understanding
A microbe as a factory
A drug here means a useful protein or other product made because a geneA sequence of DNA bases that codes for a polypeptide or a functional RNA. was inserted, not a chemical you invent a dose for. The clearest microorganism example is human insulin. The human gene is inserted into a bacterium or a yeast. The host’s ribosomeA small organelle made of rRNA and protein, where translation takes place. translate the messenger RNAA single-stranded RNA copy of a gene that carries the code from the nucleus to a ribosome., the protein is collected, and the product is human insulin rather than an extract from animal pancreas.
Bacteria grow quickly in a fermenter, so a small culture can yield a large mass of protein. The gene must have a promoter the host recognises, or the protein is not made. A codonA sequence of three bases on mRNA that codes for one amino acid or a stop signal. that is rare in the host can also slow translationMaking a polypeptide on a ribosome, using the sequence of codons on mRNA. tRNAs bring the amino acids.. You do not need those engineering details unless a question gives them. You do need: gene inserted, host transcribes and translates, product purified.
Plants and animals can be the host too
A genetically modifiedHaving DNA that has been changed by genetic engineering, often by adding a gene from another organism. plant can be made to produce a protein, including a vaccine antigenA molecule, often a protein or glycoprotein on a cell surface, that the immune system recognises as non-self. or an antibodyA Y-shaped protein made by plasma cells that binds specifically to one antigen. fragment, in its leaves or seeds. The plant is the factory. The drug is the protein, harvested and purified. A field of plants is not itself the medicine.
A genetically modified animal can carry a human gene that is expressed in the mammary gland, so the protein is secreted in milk and can be collected. The specification lists animals as producerAn organism, usually a plant, that makes its own organic molecules by photosynthesis. Producers form the first trophic level.. You do not need a brand name. The animal is not “a drug”. The protein in the milk is the product, and it still has to be purified and tested.
What this point is not
Insulin from a bacterium is not a reason to tell someone how to treat diabetes. That is clinical care. A herbicide-tolerance gene in a crop is a GMO, but it is not a drug. Keep 8.17 on products used as medicines.
The same recombinant method can make research proteins that are never licensed as drugs. “It was made in a bacterium” does not mean it is safe to inject. Safety testing is outside this sentence.
NOT: the host is not the medicine, and a herbicide-tolerance gene is not this drug point.
- Gene, host and product are three different things
- Microbes can make human insulin
- Plants and milk can also be the source
- The protein still has to be purified
Two traps this diagram blocks
- Do not call the bacterium, the plant or the animal the drug.
- Do not add a dose or a treatment plan.
From the diagram alone
Question
Describe how a microorganism can be used to produce a named human protein, and state one other kind of host. [3]
Show a model answer
The human gene, such as the insulin gene, is inserted into a bacterium or yeast. The host translates the protein, which is then collected and purified. A plant or a milk-producing animal can be the host instead.
| Host | Where the product appears | What you collect |
|---|---|---|
| Microorganism | Inside the cells or secreted into the medium | The protein, after purification |
| Plant | Leaves, seeds or another tissue | The protein, not the whole plant as a dose |
| Animal | Often milk, if the gene is switched on in the mammary gland | The protein from the milk |
Make your reasoning visible
Name the host type
The specification lists plants, animals and microorganisms. Match the example to the one the question asks for.
Gene, then protein
The inserted DNA is not the drug unless the drug is a nucleic acid. For insulin, the drug is the protein.
Key explanations
- A useful drug protein is made because a geneA sequence of DNA bases that codes for a polypeptide or a functional RNA. from another source was inserted.
Avoid this misconception
The claim: The bacterium becomes human, so its own insulin gene is switched on.
The correction: The human gene is inserted. Bacterial cells do not have a human insulin gene of their own. They translate the recombinant gene.
Order making a drug with GM bacteria
A human protein such as insulin can be made by bacteria given the human gene. Order the procedure.
Order the steps
What to do
- Reorder the cards below: drag a card (on a touch screen, drag its number), tap a card then tap where it goes, or use the ↑ and ↓ arrows at its right.
- Press Check under the cards to mark each one green (right place) or red; the count shows how many are right.
- Stuck? Hint first outlines the first wrong place, then gives a clue, then places that step for you.
- Shuffle mixes the cards again; Start again returns them to the starting order. Keyboard: Space picks up, arrow keys move, Space drops.
Put the steps for making human insulin in bacteria in order.
1 of 7 in the right place
Cutting and ligation are modelled in 8C 1. GM plants and animals (for example a protein in milk) use other vectors and are not ordered here.
Check your understanding
Try each question before opening the suggested answer.
Practice question
Retrieval and explanation · suggested answer
How can a bacterium produce human insulin?
Show suggested answer
The human insulin gene is inserted into the bacterium. The cell transcribes and translates it, and the protein is collected.
Practice question
Retrieval and explanation · suggested answer
Why is a promoter that the host recognises needed?
Show suggested answer
Without it the host RNA polymerase does not transcribe the inserted gene, so no protein is made.
Practice question
Retrieval and explanation · suggested answer
How can a genetically modified mammal be used to produce a drug?
Show suggested answer
A human gene is expressed in the mammary gland, the protein is secreted in the milk, and the protein is purified. The animal itself is not the dose.
Take the idea further
Apply the same specification knowledge to an unfamiliar problem. Any extra assumptions are supplied in the question.
Stretch question
A question asks for one drug-production example from each of microorganisms, plants and animals. Write three short sentences. Do not name a dose or a patient.
Show a hint
Host, where the gene is expressed, what is collected.
Explore the reasoning
A bacterium with the human insulin gene translates that gene and the protein is purified from the culture. A plant can be engineered so a pharmaceutical protein accumulates in a tissue such as the seed, which is then harvested. A transgenic mammal can express a human protein in milk, and the protein is purified from the milk. None of these sentences is a prescription.
Recall this lesson
Lesson recall questions
Question 1 of 5: List the three types of genetically modified organism named as drug producers in this specification point.
Drugs from GM organisms
Practice question
Retrieval and explanation · suggested answer
List the three types of genetically modified organism named as drug producers in this specification point.
Lesson: 8C 2: Drugs from Genetically Modified Organisms
Try this from memory first.
Put your biology to work
Explore where these ideas appear in the world. Enrichment, not extra required recall.
Insulin was the proof the method could make a medicine
8C · Drugs from Genetically Modified OrganismsNHGRI’s history note on the first genetic engineering company says human insulin and growth hormone genes were isolated, and that by 1982 human insulin was marketed as the…Specification 8.17Read & use the scienceClose article
Why this matters
NHGRI’s history note on the first genetic engineering company says human insulin and growth hormone genes were isolated, and that by 1982 human insulin was marketed as the first recombinant DNA drug. The same note lists later proteins such as a clotting factor and a hepatitis B vaccine. Use that as history, not as a list you must memorise, and not as treatment advice. 8.17: microorganisms were the first factories. Plants and animals use the same idea of an inserted gene whose protein is the product.
Back to the specification
Pearson Edexcel IAL Biology · Issue 2, February 2021 · Unit 5, pp. 35–38. The application extends beyond required recall.
- 8.17 Drugs made using genetically modified organisms.
Use the science
Why is animal-pancreas insulin not an example of 8.17?
Explore a possible response
8.17 is production using a genetically modified organism. Extracting a protein from an unmodified pancreas does not involve an inserted gene.
Explore the source
- NHGRI: 1976 first genetic engineering companyUS National Human Genome Research Institute
Insulin was a manufacturing milestone
8C · Drugs from Genetically Modified OrganismsThe FDA’s history records the development of biosynthetic human insulin using recombinant DNA in bacteria and its first approval in 1982. The achievement was not just inserting a…Specification 8.17Read & use the scienceClose article
Why this matters
The FDA’s history records the development of biosynthetic human insulin using recombinant DNA in bacteria and its first approval in 1982. The achievement was not just inserting a gene: the organism had to make a useful protein that could be produced, purified and quality-checked as a medicine. That is the distinction between the method in 8.18–8.19 and the product in 8.17. A student should not assume that every genetically modified organism is released into the environment; drug-producing microorganisms can be grown in controlled facilities. This is a manufacturing and regulation story, not advice about an individual’s diabetes treatment.
Back to the specification
Pearson Edexcel IAL Biology · Issue 2, February 2021 · Unit 5, pp. 35–38. The application extends beyond required recall.
- 8.17 Drugs made using genetically modified organisms.
Use the science
Why is a bacterium containing a human gene not yet proof that a usable insulin medicine has been made?
Explore a possible response
The inserted gene must be expressed to make the correct protein, and the product must be purified, tested and manufactured consistently before use as a medicine.
Explore the source
- 100 years of insulinUS Food and Drug Administration