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When preparing and showing the production of alcohol by yeast, how many steps are there?
- 11 steps
- 1. Add glucose to 2 conical flasks
- 2. Add yeast to one flask, second- no yeast
- 3. Label the flasks
- 4. Half fill fermentation locks with water
- 5. Put flasks in water bath(30*)
- 6. Result- fermentation is done when bubbles stop (test to know CO2 made-limewater)
- 7. Filter into separate boiling tubest
- 8. Add potassium iodide
- 9. Add sodium hypochlorite
- 10. Put boiling tubes in water bath(60*)
- 11. Expected result: yellow crystals
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When preparing and showing the production of alcohol by yeast, what is the expected result?
- Yellow crystals in yeast+glucose solution
- None in control
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When preparing and showing the production of alcohol by yeast, what is first added to both conical flasks?
Add glucose solution to each of 2 conical flasks
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When preparing and showing the production of alcohol by yeast, what is added to only one of the conical flasks that already had glucose solution?
Add yeast Bone in second flask- control
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When preparing and showing the production of alcohol by yeast, what is the control?
Conical flask with glucose solution but no yeast added to it.
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When preparing and showing the production of alcohol by yeast, what are the flasks labelled?
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When preparing and showing the production of alcohol by yeast, what is the fermentation lick filled with and by how much?
Half fill the fermentation locks with water and put one on each flask
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When preparing and showing the production of alcohol by yeast, how can an anaerobic condition be ensured?
Put layer of oil on top
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When preparing and showing the production of alcohol by yeast, flasks are placed to water bath at what temperature?
- Stand flasks in water bath at 30* for 24 hrs
- Affected by temp as fermentation is controlled by enzymes)
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When preparing and showing the production of alcohol by yeast, what is the result of the flasks standing in water bath at 30* for 24hrs?
- Fermentation is complete when the bubbles stop.
- To know CO2 was being produced test by using lime water which turns lime water milky.
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When preparing and showing the production of alcohol by yeast, how do you test to know if CO2 was being produced?
Use lime water which turns lime water milky
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When preparing and showing the production of alcohol by yeast, what is done after fermentation is complete?
Filter the contents of each flask into separate boiling tubes and add potassium iodide and sodium hypochlorite to each by dropper an syringe.
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When preparing and showing the production of alcohol by yeast, what is added to the boiling tubes before being placed in the 60* water bath?
- Add potassium iodide by dropper
- Add sodium hypochlorite by syringe
- Place boiling tubes in water bath at 60* for 4-5mins.
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What is the difference between the productions of aerobic respiration and anaerobic respiration?
- H2O is produced at end of aerobic respiration.
- H2O is not produced at end of anaerobic respiration.
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When preparing and showing the production of alcohol by yeast, what is the test for the presence of alcohol?
Idoform test - uses potassium iodide, sodium hypochlorite, water bath at 60*.
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When preparing and showing the production of alcohol by yeast, what equipment is used? (12)
- Conical flasks
- Glucose solution
- Yeast
- Fermentation locks with water
- Water bath (at 30* and 60*)
- Lime water (to test CO2 was being produced)
- Boiling tubes
- Potassium iodide
- Dropper
- Sodium hypochlorite
- Syringe
- Thermometer
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