Is Yeast Alive?

Question: Is yeast alive?

1. Hypothesis- I think yeast is alive because it is a bacteria, and since bacteria is alive, yeast is also alive.

2. Materials- 4 test tubes, 4 packets of yeast, 2 packets of sugar, 4 balloons,

3. Procedure- set up four test tubes and label then 1-4. fill test tube 1 4/5 full of warm tap water and add 1 packet of dry yeast a little at a time and mixing at the same time. Mix by putting thumb over top of test tube and gently shaking. Pour the solution into the other three test tubes so all have the same amount. Add half a packet of sugar to test tubes one and two. Add warm tap water to each test tube, 4/5 of the way full. Cover each test tube with a balloon to seal the end of the test tube, then hold finger over end of test tube and shake vigorously. observe test tubes every 5 minutes for 25 minutes and record observations.

4. Background research- the principle of yeast is fermentation because yeast ferments when it is combined with water and sugar to produce carbon dioxide.

5. Safety procedures- to remain safe, goggles would be advised as well as aprons in case solution can not be contained in test tubes.