Chapter 18: Biotechnology and Genetic Modification

This chapter is included in the 5090 O Level syllabus and is relevant for IGCSE and GCSE as well, based on the 2023 syllabus.

Topics Covered

Role of Yeast
- Yeast is used in the production of bread and ethanol.
- Bread Making Process: Traditional Method
  - Warm water, sugar, and yeast are added, left for proofing.
  - Flour is added to make a dough, kneaded, allowed to rise, punched, divided, reshaped, and baked.
- Fermentation
  - Breakdown of sugars by bacteria and yeast without oxygen.
  - Produces ethanol and carbon dioxide.
  - Ethanol at 15% concentration halts fermentation due to toxicity.
  - Glucose is converted into ethanol (C2H5OH) and CO2.
Use of Bacteria in Biotechnology and Genetic Modification
- Rapid reproduction rate (binary fission every 20 minutes).
- Ability to produce complex molecules (e.g., insulin).
- No ethical concerns like those associated with animal products.
- Presence of plasmids useful for genetic manipulation.
Fermenters
- Used for large-scale production of products by bacteria and fungi.
- Conditions to control: temperature, pH, oxygen, nutrient supply, waste products.
Use of Enzymes in Various Industries
- Biological Washing Powders
  - Enzymes help remove protein stains (e.g., egg, blood, grease).
- Fruit Juice Production
  - Enzymes like pectinase are used to clear fruit juice.
- Lactose-Free Milk
  - Lactase enzyme breaks down lactose into glucose and galactose for those with lactose intolerance.

Bacteria are advantageous in biotechnology due to their rapid reproduction, ethical neutrality, and genetic manipulability.
Yeast and bacteria play significant roles in food production (e.g., bread, wine, cheese).
Understanding of fermentation and enzyme use is crucial for applications in industry and food technology.

This section concludes the discussion on biotechnology. Further insights on genetic modification and applications will follow in subsequent lessons.