# The Scientific Method: Yeast Lab

Topics: Yeast, Bread, Scientific method Pages: 4 (1240 words) Published: October 28, 2012
The Scientific Method- Yeast Lab
Objective:
1. To learn about the steps of the scientific method
2. To be more familiar with the lab equipment
3. To find what temperature can affect the respiration of yeast bubbling Hypothesis:
1. If the temperature of the beaker is less than 10oC, then the yeast will not reproduce 2. If the temperature of the beaker is between 20-27oC, then the yeast will reproduce but slowly 3. If the temperature of the beaker is between 35-40oC, then the yeast will reproduce rapidly 4. If the temperature of the beaker is greater than 90oC but not boiling, then the yeast will barely reproduce Materials:

Four test tubes Stoppers
Eight beakers Hotplate
Four thermometer Sugar (3.5 g)
Water (15 mL) Yeast (1.5 g)
Safety goggles Ice Bath
Weighing paper Timer
Triple beam balance

Procedure:
1. Take your test tube and add 1.5g of yeast, 3.5g sugar, and 15mL of water. (Repeat this three more times) 2. Mix the solution until it is has a smooth texture.
3. Grab four beakers and fill them with water about to the half way. Take two and place on separate hotplates, in the other place ice in, and leave one beaker untouched. 4. Once each beaker reaches the desired temperature then place the test tubes in, make sure the stopper is placed on top, and take the tip of the stopper and place into a separate beaker filled with water. 5. When the test tube is placed set a timer for fifteen minutes and record how many gas bubbles are produced each minute. (Do this for each tube in their different temperature beaker) 6. Once you have gathered information find the averages and totals from your group as well as your class and other classes. 7. Clean up your station

8. When all your information is collected use you quantitative data and create two graphs one for you group respiration results and one for the class respiration results.

Research: In the “tree of life” yeast is a...

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