You will use beakers and test tubes in this activity. Take care when handling glassware.
The process of cellular respiration may be complex, but it is actually fairly simple to study. One of the products of cellular respiration is carbon dioxide gas, so if cellular respiration is taking place, one should be able to collect it in a sealed environment.
Yeast is an example of an organism that converts sugars into carbon dioxide via the process of cellular respiration. Yeast is particularly effective at this task, so much so that it is often used as an ingredient in baked goods. The carbon dioxide produced by the yeast makes dough rise.
In this lab, yeast will be used to determine specific conditions that are required for cellular respiration.
Question
What raw materials and conditions are involved in cellular respiration?
Materials and Equipment
felt marking pen
five plastic straws
beaker
graduated cylinder
5 narrow-necked plastic bottles
5 round balloons
sugar
salt
dry powdered yeast
warm water (between 40 and 45 degrees Celcius)
Dry Lab
A "dry lab" activity includes collected data and/or a video solution for your convenience. You can simply watch the following video and use the provided data, or if you wish to perform this lab for yourself, follow the procedure steps 1 through 12 described in the video. The same steps are included in written form in the documents available for download on the bottom of this page.
Forming Conclusions
A student performing the procedure steps 1 through 12 collected the following results.
Bottle
Contents
Observations
A
Yeast alone
Balloon did not inflate
B
Yeast and 5ml of salt
Balloon did not inflate
C
Yeast and 5ml of sugar
Balloon inflated a moderate amount
D
Yeast and 30ml of sugar
Balloon inflated a large amount
E
No yeast and 5ml of sugar
Balloon did not inflate
Based on these results, what is your conclusion regarding the requirements for cellular respiration?
A student designs an experiment similar to procedure steps 1 through 11, but sets up the whole apparatus twice, and places one set of bottles in bright light and the other set of bottles in dim light. What would you expect for the results of this experiment?
A student designs an experiment similar to procedure steps 1 through 11, but sets up the whole apparatus twice, and places one set of bottles in a warm location, and the other set of bottles in a refrigerator. What would you expect for the results of this experiment?
Is carbon dioxide the only product of cellular respiration? Explain.
