# Design Lab

Topics: Sugar, Glucose, Fructose Pages: 3 (276 words) Published: March 20, 2011
Measuring the rate of cellular respiration in yeast within different types of sugar Aim/Reasearch Question: How can the rate of cellular respiration be measured to find out if sucrose, dextrose, lactose, or maltose lets the yeast to respire more than others. Hypothesis: I think, dextrose yeast solution will respire the most number of bubbles because it is the simplest sugar to break. Materials:

* Knut
* Dropper
* Warm water
* Yeast Solution
* Sucrose
* Dextrose
* Lactose
* Maltose
Variables:
Independent Variables:
* The type of sugar
Dependent Variables:
* The number of bubbles counted as output
Controlled Variables:
* Amount of sugar
* Amount of yeast solution
* Amount of water
* Time
Procedure:
1. Prep the yeast solutions in 500ml beakers by adding the wild yeast powder and water in the beaker. (Repeat this step with four other 500ml beakers) 2. Add sucrose to one beaker filled with yeast, add maltose with the other, add lactose with another, and finally, add dextrose to the last one. 3. Put in sucrose-yeast solution with the dropper and rinse off any excess yeast that is on the outside of the dropper 4. Prepare as shown in the diagram below :

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5.) Record how many bubbles come out after 5 minutes
6.) Repeat steps 2-5 with maltose yeast solution (not sucrose yeast solution) 7.) Repeat steps 2-5 with lactose yeast solution (not sucrose yeast solution) 8.) Repeat steps 2-5 with destrose yeast solution (not sucrose yeast solution)

Table 1 : Number of bubbles released from yeasts with different sugars after 5 minutes | Dextrose-yeast solution| Sucrose-yeast solution| Maltose-yeast solution| Lactose-yeast solution| Number of bubbles released after 5 min| | | | |

Conclusion: ____________________________________________________________

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