4.8 to prepare and show the production of alcohol by yeast
DESCRIPTION
4.8 To prepare and show the production of alcohol by yeast. Before you start get or make a copy of this Table of results. Step 1. Add 200 ml glucose solution to each of two conical flasks. Step 2. Add 5 g of yeast to one flask. The second flask contains no yeast – this acts as a control. - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: 4.8 To prepare and show the production of alcohol by yeast](https://reader033.vdocuments.site/reader033/viewer/2022061618/568130e3550346895d96f8a7/html5/thumbnails/1.jpg)
4.8 To prepare and show the production of alcohol by yeast
![Page 2: 4.8 To prepare and show the production of alcohol by yeast](https://reader033.vdocuments.site/reader033/viewer/2022061618/568130e3550346895d96f8a7/html5/thumbnails/2.jpg)
Before you start get or make a copy of this
Table of results
FlaskOriginal colour
of filtrateFinal colour
of filtrateOther
changes
Yeast + Glucose solution
Control (no yeast)
![Page 3: 4.8 To prepare and show the production of alcohol by yeast](https://reader033.vdocuments.site/reader033/viewer/2022061618/568130e3550346895d96f8a7/html5/thumbnails/3.jpg)
Step 1
Add 200 ml glucose solution to each of two conical flasks.
![Page 4: 4.8 To prepare and show the production of alcohol by yeast](https://reader033.vdocuments.site/reader033/viewer/2022061618/568130e3550346895d96f8a7/html5/thumbnails/4.jpg)
Step 2
Add 5 g of yeast to one flask. The second flask contains no yeast – this acts as a control.
![Page 5: 4.8 To prepare and show the production of alcohol by yeast](https://reader033.vdocuments.site/reader033/viewer/2022061618/568130e3550346895d96f8a7/html5/thumbnails/5.jpg)
Step 3
Label the flasks:
‘Yeast + Glucose’ and ‘Control’
![Page 6: 4.8 To prepare and show the production of alcohol by yeast](https://reader033.vdocuments.site/reader033/viewer/2022061618/568130e3550346895d96f8a7/html5/thumbnails/6.jpg)
Step 4
Half fill the fermentation locks with water and put one on each flask.
![Page 7: 4.8 To prepare and show the production of alcohol by yeast](https://reader033.vdocuments.site/reader033/viewer/2022061618/568130e3550346895d96f8a7/html5/thumbnails/7.jpg)
Step 5
Stand the flasks in a water bath at 30°C for 24 hours.
![Page 8: 4.8 To prepare and show the production of alcohol by yeast](https://reader033.vdocuments.site/reader033/viewer/2022061618/568130e3550346895d96f8a7/html5/thumbnails/8.jpg)
Result:
Fermentation is complete when the bubbles stop.
![Page 9: 4.8 To prepare and show the production of alcohol by yeast](https://reader033.vdocuments.site/reader033/viewer/2022061618/568130e3550346895d96f8a7/html5/thumbnails/9.jpg)
Step 6
Filter the contents of each flask into separate boiling tubes.
![Page 10: 4.8 To prepare and show the production of alcohol by yeast](https://reader033.vdocuments.site/reader033/viewer/2022061618/568130e3550346895d96f8a7/html5/thumbnails/10.jpg)
Step 7
Add 3 ml potassium iodide to each boiling tube.
![Page 11: 4.8 To prepare and show the production of alcohol by yeast](https://reader033.vdocuments.site/reader033/viewer/2022061618/568130e3550346895d96f8a7/html5/thumbnails/11.jpg)
Step 8
Add 5 ml sodium hypochlorite to each boiling tube.
![Page 12: 4.8 To prepare and show the production of alcohol by yeast](https://reader033.vdocuments.site/reader033/viewer/2022061618/568130e3550346895d96f8a7/html5/thumbnails/12.jpg)
Step 9
Place boiling tubes in a water bath at 60°C for 4-5 minutes.
![Page 13: 4.8 To prepare and show the production of alcohol by yeast](https://reader033.vdocuments.site/reader033/viewer/2022061618/568130e3550346895d96f8a7/html5/thumbnails/13.jpg)
Expected result
![Page 14: 4.8 To prepare and show the production of alcohol by yeast](https://reader033.vdocuments.site/reader033/viewer/2022061618/568130e3550346895d96f8a7/html5/thumbnails/14.jpg)
Table of results:
FlaskOriginal colour
of filtrateFinal colour
of filtrateOther
changes
Yeast + Glucose solution
Control (no yeast)
![Page 15: 4.8 To prepare and show the production of alcohol by yeast](https://reader033.vdocuments.site/reader033/viewer/2022061618/568130e3550346895d96f8a7/html5/thumbnails/15.jpg)
END