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SUGAR SUBSTITUTE EFFECT ON YEAST RESPIRATION. By: Peter Szalay Grade 9 Central Catholic. Cell Respiration. Sucrose ( C 12 H 22 o 11 ). Disaccharide of glucose and fructose Linked via their anomeric carbons. Produced naturally in plants eg. Sugar cane or sugar beet.
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SUGAR SUBSTITUTE EFFECT ON YEAST RESPIRATION By: Peter Szalay Grade 9 Central Catholic
Sucrose (C12H22o11) • Disaccharide of glucose and fructose Linked via their anomeric carbons. • Produced naturally in plants eg. Sugar cane or sugar beet. • functions as an energy store for metabolism and as a carbon source for biosynthesis. • Most common sweetener in the modern world
Sucralose (C12H19Cl3o8) • Artificially created sweetener and is a sugar substitute • Non-caloric due to the body not being able to metabolize it • 1,000 times sweeter than sucrose
Saccharomyces cerevisiae (Bakers Yeast) • Best known for alcohol fermentation and bread baking. • Yeast is the most investigated cell in the world. • Used in microbiology due to its ease of manipulation and rapid growth. • Eukaryotic, shares biochemistry with more advanced organisms.
Purpose Hypotheses • To investigate sucralose effect on yeast respiration. • Alternate Hypothesis: The yeast will be able to metabolize sucralose yielding more CO2 than the control. • Null Hypothesis: The yeast will not be able to metabolize the sucralose more than the control.
Materials • Rapid Rise Saccharomycescerevisiae, Red Star brand • Micro Pipettes • Macro Pipettes • Balloons (9” Rounds) • 125 ml Erlenmeyer Flasks • Deionized Water • Sucrose • Sucralose • 100mL Graduated Cylinders • Plastic Tub • Plastic Film Wrap
Procedure • The Sucrose and sucralose were dissolved in sterile water at a concentrations of (10%). • The sugar solutions were added to 5 flasks each in the ratios as seen below. • 2.5 grams of Red Star rapid rise Cooking Yeast was added to each flask and balloons were immediately affixed to each flask. • The flasks were transferred to a warm (35 C) water bath. • After 60 minutes of incubation, each balloon was removed from the flask (careful to prevent any leakage of gas; each balloon was pinched at the neck and twisted off). • A plastic tub was filled with water. • Each graduated cylinder was filled with water to the brim and sealed with plastic wrap. • The cylinder was inverted and immersed into the water and the plastic wrap removed. • The balloon was placed into the water with the mouth placed into the cylinder.1 • The mouth was slowly released and the air was pumped into the graduated cylinder. The volume of gas was then recorded.
Carbohydrate effect on Yeast Respiration P = 1.891 x 10–12
Conclusions • Fail to reject the null hypothesis • Dunnett’s test showed that there was not a significant difference between the control and either of the tests of sucralose. • Also, there was a significant difference between 0.20% sucrose and 0.20% sucralose, and a difference between 2% sucrose and 2% sucralose.
Limitations of project • Slight variation in when data was recorded • A larger sample size would be needed to get more accurate data. • Not all the CO2 that was produced by the yeast rose into the balloon.
Extensions to the project • The sugars can be tested for the survivorship of the yeast • Other types of carbohydrates can be tested on their effects on yeast respiration. • Other compounds such as honey can be tested for their effect on yeast as well • Test for yeast cell population growth • Test for other health factors in yeast
References • Otterstedt, Karin et al. “Switching the mode of metabolism in the yeast Saccharomyces cerevisiae” EMBO reports vol. 5,5 (2004): 532-7. • “Effect of Different Isomers of Sugar on Yeast Respiration.” California State University, Northridge, Nov. 2005, www.csun.edu/scied/2-longitudinal/schuster/index.html. • “Basic Science: Understanding Experiments.” OpenLearn, The Open University, www.open.edu/openlearn/ocw/mod/oucontent/view.php?id=19988§ion=2.3. • Libretexts. “Cellular Respiration.” Biology LibreTexts, Libretexts, 20 Feb. 2016, bio.libretexts.org/Ancillary_Materials/Experiments/General_Biology_Labs/Cellular_Respiration. • Kayikci, Ömur and Jens Nielsen. “Glucose repression in Saccharomyces cerevisiae” FEMS yeast research vol. 15,6 (2015): fov068.
ANOVA (Whole set) Summary of Data Treatments 0%0.2% SR 2% SR 0.2% SL2% SL Total N 5 5 5 5 5 25 ∑X 71 130 789 81 117 1188 Mean 14.2 26 157.8 16.2 23.4 47.52 ∑X2 1071 3430 128655 1339 2743 137238 Std.Dev. 3.9623 3.5355 32.2134 2.5884 1.1402 58.0173 Result Details Source SS df MS Between-treatments 76488.64 4 19122.16 F = 89.03138 Within-treatments 4295.6 20 214.78 p=1.891 x 10–12 Total 80784.24 24
ANOVA comparing 0.2% concentrations Summary of Data 0.2% SL0.2% SRTotal N 5 5 10 ∑X 81 130 211 Mean 16.2 26 21.1 ∑X2 1339 3430 4769 Std.Dev. 2.5884 3.5355 5.9339 Result Details Source SS df MS Between-treatments 240.1 1 240.1 F = 25.01042 Within-treatments 76.8 8 9.6 p=0.00105 Total 316.9 9
Anova comparing 2% concentrations Summary of Data Treatments 2% SR 2% SL 3 4 5 Total N 5 5 10 ∑X 789 117 906 Mean 157.8 23.4 90.6 ∑X2 128655 2743 131398 Std.Dev. 32.2134 1.1402 74.0228 Result Details Source SS df MS Between-treatments 45158.4 1 45158.4 F = 86.92666 Within-treatments 4156 8 519.5 p=1.428 x 10-5 Total 49314.49