Fermentation in a Bag Lab Purpose: to observe the process of fermentation in a living organism, yeast (Saccharomyces) Materials: Sugar, salt ,flour, yeast, 4 small bags labeled, water Procedure 1. Label the 4 bags FLOUR, SALT. 1TBS sugar, ½ tbs sugar 2. #1- ½ tsb of flour and 1/8 tea. Of yeast. #2 ½ tbs.of sugar, ¼ tea. Salt, 1/8 teas. Of yeast. #3 1 TBS of sugar and 1/8 tea. Of yeast #4 ½ TBS. of sugar and 1/8 teas. Of yeast. 3. Go to the sink area and add 1 TBS. of the lukewarm water. 4. Put bags on a white tray and put in the fridge. Pre- lab questions 1. What is fermentation? How does fementation relate to respiration? 2. Which bag do you think will expand the most? Why? Data: Observe the bags after 45 minutes. ( use timer) Rate the expansion of each bag from 1-4 in a graph. Clean-up Rinse bags out in the sink and throw them away in the trash. Questions: 1. Which bag expanded the most? Why do you think that was? 2. What made the bags expand? Why was this gas produced? 3. Why was yeast one of the first animals we domesticated? What do we use yeast for?