21.1.1Biotechnology and Genetic Modification
Usefulness of Bacteria — Cambridge IGCSE Biology 0610 Revision Notes & Topical Questions
5 min read 5 parts Lesson 4 of 4 Unit quiz
Curriculum Equation Key قوانين الرقم الهيدروجيني والاتزان الأيوني - pH & Acid-Base Equilibrium FormulasFast Exam Solution
pH = -log[H⁺] | pOH = -log[OH⁻] | pH + pOH = 14 | [H⁺][OH⁻] = 10⁻¹⁴
Word Equation & Conditions: الرقم الهيدروجيني = -لوغاريتم تركيز أيون الهيدروجين | pH + pOH = 14
Location & Specifications: الاتزان الأيوني، كيمياء 3 ثانوي، التحصيلي، و AP Chemistry.
Part 1 of 5Microorganisms in Biotechnology
Biotechnology uses living organisms to make foods and other useful substances.
Microorganisms
- Microorganisms Small living organisms such as bacteria and yeast can be grown in large numbers to make products for humans.
Bacteria
- Bacteria The most common microorganisms used in biotechnology are bacteria, because of several useful features.
Foods
- Foods Some foods are made by adding bacteria, for example certain bacteria turn milk into yoghurt.
Other substances
- Other substances Bacteria can also be used to make chemicals, medicines and fuels.
Part 2 of 5Core Reasons Bacteria Are Useful
Core Reasons Bacteria Are Useful
Complex molecules
- Complex molecules Bacteria can make complicated molecules, such as enzymes and proteins, that would be difficult to produce any other way.
Rapid reproduction
- Rapid reproduction Bacteria divide very quickly, so their numbers and the amount of product they make can rise rapidly.
Yoghurt example
- Yoghurt example Bacteria added to milk produce enzymes that change the milk into yoghurt.
Large scale
- Large scale Because they multiply fast, huge populations can be grown in containers called fermenters.
| Feature of bacteria | Benefit to biotechnology |
|---|---|
| Make complex molecules | Useful products such as enzymes and proteins |
| Reproduce rapidly | Product amounts increase quickly |
| Few ethical issues | Large numbers can be grown in laboratories |
| Contain plasmids | DNA can be transferred between cells |
Part 3 of 5Extra Advantages (Extended)
Few ethical concerns
- Few ethical concerns Growing large numbers of bacteria in a laboratory raises far fewer ethical objections than using animals.
Plasmids
- Plasmids Bacteria contain small rings of DNA called plasmids, which are an ideal way of moving DNA from one cell to another.
Genetic manipulation
- Genetic manipulation A useful gene can be inserted into a plasmid and carried into a bacterial cell so it makes the required protein.
Simple needs
- Simple needs Bacteria can be grown in controlled laboratory conditions without needing a large amount of space.
Part 4 of 5Linking to Genetic Modification
The features above explain why bacteria are chosen as host cells.
1
A human or other gene is cut out of its source DNA and placed into a plasmid.
2
The plasmid is taken up by bacterial cells, which now contain the new gene.
3
The bacteria reproduce rapidly, producing many copies of the gene and of the protein it codes for.
4
The product is collected from the bacterial culture and purified for use.
Part 5 of 5Exam Checklist & Tips
21.1.1 – Key Points for the Exam
- Biotechnology The use of living organisms to make useful products or carry out useful processes.
- Bacterium A single-celled organism without a nucleus, often used in industry.
- Plasmid A small ring of DNA in bacteria that can carry genes between cells.
- Fermenter A large vessel in which microorganisms are grown to make a product.
Common Mistakes
- Saying bacteria are useful only because they cause disease;
- the features are rapid reproduction and making complex molecules.
- Writing that bacteria make yoghurt directly rather than producing enzymes that change the milk.
- Confusing a plasmid with the main chromosome; plasmids are small extra rings of DNA that can be transferred.
- Describing bacteria as having no ethical concerns at all instead of fewer ethical concerns than larger organisms.
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