1. Try This: Yeast vs. Sand p. 3 First and Last NameDate Question What makes yeast different from sand?

2. Observations: 1a) Get 5 ml of sand, and 5 ml of yeast. Compare the texture, colour, and size of the grains: FeatureSandYeast TextureRoughSmooth Colour(s)Mostly whiteBeige SizeLargerSmaller ShapeIrregular crystals Ovals/rods

3. 2b) Predict what will happen when you add sand and yeast to sugared water: 2b) When I add sand to sugared water, it will….. When I add yeast to sugared water, it will…

4. 3. Add 20 ml of sugared water to two graduated cylinders. Add the sand to one, and the yeast to the other. Wait a few minutes, then record what happens in each. 3c) The sand….sank to the bottom. No changes were visible. The yeast….sank at first, then floated. The water became cloudy, and bubbles rose to the top.

5. 3d) Why was it important to use an equal amount of sand and yeast, and sugared water in each grad. Cylinder? 3d) It was important to use the same amount of sand and yeast, and the same amount of sugared water in each graduated cylinder because then it’s a fair test. If you had too little of one material, you might not get a reaction, giving an incorrect conclusion.

6. 3e) Speculate about what happened in the yeast container. (Try to explain why the yeast produced bubbles.) 3e) The yeast produced bubbles because… They are a waste product of the yeast using the sugar and water. Yeast “eats” the sugar and water, to make energy. Carbon Dioxide is the waste product, forming bubbles.

7. 3f) How does this activity illustrate one way to distinguish living things from non-living? 3f) One way to tell that something is living is if it reacts with a food source and produces a waste product.

8. Clean up! After you are done, pour the sugar water and yeast down the sink and rinse out the graduated cylinder. Use the test tube brush if necessary Drain most of the water out of the graduated cylinder with sand and shake the sand into the garbage can. Do NOT pour the sand down the sink. Rinse the graduated cylinder. Use the test tube brush if necessary.

9. Finished early? 1. What gas is in the bubbles? 2. What do we use yeast for in A) bread-making? B) wine production? 3. Why can’t you get drunk from eating bread?

10. Watch yeast budding, (reproducing) http://www.youtube.com/watch?v=BTHYa f-EuYs