Crop Plants
Microorganisms
5.5 Understand the role of yeast in the production of beer.
Role of yeast in beer production:
Fermentation is anaerobic respiration by yeast (fungus):
Glucose → ethanol + carbon dioxide
Process:
Fermentation is anaerobic respiration by yeast (fungus):
Glucose → ethanol + carbon dioxide
Process:
- Barley seeds are germinated (warm, moist)
- Seeds make amylase which converts: starch → maltose (sugar)
- Yeast is added to ferment the sugars to produce alcohol
- Hops are added for flavour
5.6 Describe a simple experiment to investigate carbon dioxide production by yeast, in different conditions.
- Place a test tube of yeast in glucose solution.
- Put a layer of oil on top if you want the yeast to respire anaerobically (as it will prevent oxygen entering the solution.)
- Put the test tube in a water bath, heat the water to vary the temperature.
- Collect gas coming off in a tube then: count the bubbles; use downwards displacement.
Fish Farming
5.9 Explain the methods which are used to farm large numbers of fish to provide
a source of protein, including maintenance of water quality, control of
intraspecific and interspecific predation, control of disease, removal of waste
products, quality and frequency of feeding and the use of selective breeding.
Here is a little brochure I made for Fish Farming.