The Negative Affects on Yeast ‘s Cellular Respiration in the Presence of a Pollutant
Author Name: Shuhan Jia
Instructor: Dr. Kim Largen
Lab Section: EVPP110 – 202
Date: April 18, 2020
In this experiment, different types of contaminants were studied to examine their
effects on cell repair rates. Cellular respiration is a very important process because it
converts energy and affects the concentration of carbon dioxide. The rate of cellular
respiration is determined by the volume of carbon dioxide gas. Several different activities
were used to measure the rate of cellular respiration. In the first activity, two culture
tubes were compared, one containing yeast and water, the other yeast water and sugar.
This was done to show that carbohydrates speed up cellular respiration. The second
activity involved 8 simulated pollutants and the amount of CO2 produced when they
were mixed with the combination of yeast and sugar. After these activities were done it
was concluded that the addition of sugar to yeast caused an increase in the amount of
CO2 produced, showing a rise in the rate of cellular respiration, and (had the experiment
been conducted correctly and without error) that pollutants would have caused a lower
rate of cellular respiration when interacting with yeast and sugar than if they did not
interact with the yeast and sugar. This was shown by the amount of CO2 produced.
Jia 3 Introduction
The objective of the study is to illustrate the difference in the rate of cellular
respiration when dealing with only water and yeast, versus the combination of yeast
water and sugar. The objective was also to show the effects of other different pollutants
on the rate of cellular respiration. Cellular respiration is one of the important ways a cell
gains useful energy to fuel cellular activity. It is a process that transforms energy and
affects the concentrations of carbon dioxide and oxygen in air and water (Proppe et al.,
2007). It is a metabolic process, and in this case creates CO2 when yeast, which is a
living fungus in the phylum Ascomycota eats away at the carbohydrate (sugar) resulting
in a waste product- CO2 (Cannon et al., 2008). The rate of cellular respiration will be
seen by the amount of CO2 produced. Carbon dioxide gas is found in minor proportions
in the atmosphere. It is assimilated by plants which then produce oxygen by
photosynthesis. (Montzka, 2011). The objective of this experiment was to understand the
importance of cellular respiration as a central aspect of existence along with the effect of
the rate of cellular respiration in regard to the availability carbohydrate as determined by
production of carbon dioxide.
Yeast will have a higher rate of cellular respiration in the presence of a source of
carbohydrate than it would without a source of carbohydrate. This will be shown by the
amount of CO2 produced in the experiment. Yeast will have a lower rate of cellular
respiration in the company of a carbohydrate (sugar) and another pollutant than it would
with a carbohydrate and the absence of a simulated pollutant. This is shown by the
amount of CO2 produced. These are the developed hypotheses of this experiment.
In three phases, this experiment determines the proper setting in which cellular
respiration is successful and unsuccessful.
In part A the effect of a carbohydrate on a simple organism such as yeast is tested.
This part of the experiment called for two 25 mL beakers, two 15 mL culture tubes, and
two 4-dram shell vials. In each beaker 1.25 mL dry active yeast is poured. In one of the
beakers 1.25 mL of sugar, the simulated carbohydrate, is added to the yeast. Then 13 mL
of warm water is added to both beakers. Once the warm water is properly mixed, beaker
1 is poured into culture tube and beaker 2 into a separate culture tube. Each are inverted
and the gas levels monitored.
In Part B the effect of pollutants are monitored by using 5 different simulated
pollutants: Isopropyl alcohol, vinegar, salt solution 10%, baking soda solution 10% , and
bleach solution 1%. Similar to part A, the pollutants were mixed in a beaker full of 1.25
ml of yeast and 13 mL of warm water. Then it was observed while in a culture tube. Each
lab group was given a different simulated pollutant and the results were combined,
recorded, and compared. In the final phase both a pollutant and a carbohydrate were
added in order to determine if the carbohydrate is enough to offset the pollutant.
Table 6.1 Gas (CO2) volume (mL) at one-minute intervals for ten minutes for
culture tube containing yeast and water versus culture tube containing yeast, water,
and sugar. In two different beakers Yeast + Water and Yeast + Water +Sugar are
monitored over a period of 10 minutes. Sugar is the simulated carbohydrate used to
discover the effect of a carbohydrate on cellular respiration.
Tube Gas Volume (mL) in Culture Tube
Contents 0 `1 2 3 4 5 6 7 8 9 10
1 Yeast+Water 0 0 0.05 0.05 0.07 0.08 0.08 0.08 0.08 0.09 0.09
2 Yeast+Water+Sugar 0 0 0.05 0.08 0.1 0.3 0.6 0.6 0.8 0.9 1
Table 6.2 Gas (CO2) volumes (mL) monitored at 1-minute intervals for 10 minutes for 5
different simulated pollutants. Each lab group monitored a specific simulated pollutant to.
Tube Gas Volume (mL) in Culture
Tube time (min)
0 `1 2 3 4 5 6 7 8 9 10
0 0 0 0 0 0.05 0.07 0.07 0.07 0.07 0.07
2 Vinegar 0 0 0 0 0 0 0 0.1 0.3 0.3 0.4
0 0 0 0 0 0 0 0 0.2 0.2 0.3
0 0.3 0.4 0.4 0.4 0.4 0.4 0.5 0.5 0.5 0.5
0.3 0.7 0.7 0.7 0.7 0.7 0.7 0.7 0.7 0.7 0.8
Table 6.3 Total volume of CO2 produced and cellular respiration rate (mL/min) for
8 combinations of yeast, water, sugar, and simulated pollutant.
Tube Contents Total Volume of CO2
Yeast+Water .07mL .009 mL
.1 mL .1 mL
.07 mL .1 mL
.4 mL .07 mL
.3 mL .03 mL
Yeast+Water+Sugar+ .5 mL .05 mL
.5 mL .05 mL
The first hypothesis suggests that a simple organism such as yeast will be more
successful at cellular respiration when a carbohydrate is present as opposed to when it is
not present. The second hypothesis suggests that a simple organism such as yeast will be
less successful at cellular respiration in the presence of a pollutant. The data found in
Table 6.1 proves the first hypothesis in showing that the amount of CO2 produced when a
carbohydrate is present is more significant than when it is not present. At the end of the
10-second mark the yeast with the simulated carbohydrate produced more CO2 than the
yeast without it. The data in Table 6.2 proves the second hypothesis. The simulated
pollutant stifled the growth of cellular respiration so that at the end of the 10-second mark
the growth, with each pollutant present, did not reach 1mL. Table 6.3 proves that even in
the presence of both a pollutant and a carbohydrate cellular respiration is still stifled.
Thus displaying the detrimental and irreversible effects that pollutants have on living
organisms. In conclusion this experiment highlights how important it is to be conscious
and aware of the effect we have on this environment because without it we would not be
able to survive.
Cannon PF, Minter DW, Stalpers JA. (2008). Dictionary of the Fungi. 10th ed.
Montzka, S A Non-CO2 greenhouse gases and climate change. Nature (London). 476
(7358), p. 43.
Proppe, D., & Harrel, S. (2007). The effects of photosynthesis and cellular respiration on
dissolved oxygen concentration. Science Activities, 44(1), 10-15. Retrieved from