This lab explores the concepts of Cellular Respiration and Fermentation in yeast. Yeast do Alcoholic Fermentation and one of the byproducts is Carbon Dioxide. When you bake bread with yeast, Carbon dioxide is produced, which forms bubbles in the dough, causing the dough to rise. The heat kills the yeast and the bubble pockets lighten the bread.
In this lab, you can actually see fermentation happening by measuring “bubble production”. The tricky part of this lab is setting it up. So I put together a little video to show you exactly how to do that. Special thanks to my Student Worker Brian Powers for helping me film the video. He did a pretty good job – Smooth zooming and all. Enjoy!
[flashvideo file=http://leslie-samuel.s3.amazonaws.com/YeastRespiration.flv image=http://www.interactive-biology.com/images/cellularresp.jpg /]
And here’s the actual lab. You can download it by clicking on the download link on the top left of the document. You will need Adobe Acrobat or another pdf viewer in order to download it and see it on your computer.
The following picture was taken approximately 45 minutes after the test tubes were placed in an incubator at 30 degrees Celcius. You can see that there’s CO2 production in both samples with sugar and none in the control (click image to enlarge).