Casey Bower
Biology
Mrs. Comfort
14 November 2012
The Effects of Glucose on Yeast Production of Carbon Dioxide
Statement of the Problem- Will Coke react the most in yeast to produce the most
Carbon Dioxide.
Hypothesis-if we put coke in yeast, then the yeast will produce the most carbon
dioxide.
Materials/Procedures-Refer to Lab Protocol
Results-
Table1: The Effects of Glucose on Yeast Production of Carbon Dioxide
Flask Number
1
2
3
4
5
6
7
Substance in Flask
Water
Sugar free Red Bull
Red Bull
Diet Snapple
Coke
Diet Coke
Snapple
Circumference of
Balloon (cm) after
20 minutes
10.5
13.5
24.5
10.5
17.5
11
15
Circumference of
Balloon (cm) after
40 minutes
12
14
25
17
20.5
12
14
Table 2: The Effects of Glucose on Yeast Production of Carbon Dioxide
Substance
Calories per serving
Sugar per serving (g)
Water
0
0
Sugar free Red Bull
10
0
Red Bull
110
27
Diet Snapple
5
0
Coke
140
39
Diet Coke
0
0
Snapple
110
27
Circumfrence of Balloon
The Effects of Glucose on Yeast
Production of Carbon Dioxide
30
25
Water
20
Sugarfree Red Bull
15
Red Bull
10
Diet Snapple
5
Coke
0
Start
20 minutes
40 minutes
Time in Incubator
Diet Coke
Snapple
1. If we put yeast in the drink with the most sugar, than the balloon will blow
up bigger than the drink with the least amount of sugar. I just guessed my
hypothesis and it was accepted.
2. Yeast is a type of fungus. Yeast just like humans go through Cellular
Respiration to obtain energy. After glucose diffuses into a yeast cell, it goes
through alcoholic fermentation. When glucose is broken in half forming
providing pyruvic acid, energy is released. The chemical reaction is pyruvic
acid + NADH -> ethyl alcohol + CO2 + NAD+
3. In this lab, we found that the drink with the most sugar reacted the most to
the yeast. This happened because Cellular Respiration requires glucose, so
the yeast reacts the most when a lot of glucose is added. The first group that
was just in water acted as a control group so that we could see the reactions
of the other groups.
4. In conclusion, the drinks with the most sugar reacted the most to the yeast.
There are some errors that could have occurred during this experiment. One
error could be the amount of the drink that was poured into the flask, I know
that in my group we spilled some of our drink while pouring the drinks into
the flask. Another error could be the amount of yeast poured into each flask
because some groups had the yeast stuck to the funnel so all of it did not go
into the flask. The final error could be the time spent in the incubator, each
time a group put their flasks in the incubator, it opened and let some heat out
which could have effected the results. I would have each group put their
flasks in at the same time and have the drinks poured into the flask last so
that the yeast wouldn’t stick to the funnel and have the drinks already in the
flasks so that we wouldn’t spill it.