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The aim of the experiment: To investigate the effect of different glucose concentrations on the rate of fermentation.

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INTRODUCTION The aim of the experiment: To investigate the effect of different glucose concentrations on the rate of fermentation. Research question:How does changing the concentration of the glucose solutions will affect the rate of fermentation. Background Information: There are various factors that affect the rate of fermentation. These are; "Fermentation time This factor determines the amount of time yeast gets to act on the sugars present in the ferment, whether it be a sponge, brew, or a straight-dough. While the rate of fermentation declines with time at a constant temperature, it does not completely stop. However, the longer the fermentation time, the higher the degree of fermentation. Fermentation temperature Like any other living cell, the various enzymatic activities of the yeast cell are closely tied to the temperature of the environment. Therefore, higher ferment temperatures increase yeast activity, and vice-versa. Published literature indicates that within the range of temperatures in which yeast is operative, every one degree rise in temperature increases the rate of yeast fermentation by 3-5%. Level of water: Generally, stiffer dough take longer to ferment as compared to slacker ones. With additional water, the soluble solids are diluted and the osmotic pressure on the yeast cells is reduced. This causes an increase in yeast activity and the overall rate of fermentation. ...read more.


The solution was mixed completely and set aside. * Then the solution is seperated and put into 5 test tubes with 15ml in each. * Then 5 ml of %5 glucose solution is added to each test tubes. * The top of the test tubes are covered with parafilm so that the CO2 won't be released after fermentation. * The initial height of solution in each test tube is measured with a ruler and noted. * A 500 ml beaker which is filled with 200ml water,is placed on the burner turner and heated to 30 degree Celcius . * All 5 test tubes are placed inside the 500 ml beaker and heated for 10 minutes. * In order to keep the temperature around 30 degree Celcius(which is the most propriate temperature for fermentation)water is added to the 500 ml beaker. * The final height of the gas bubble was recorded at the top of the tube for all 5 test tubes after 10 minutes. * The carbon dioxide produced by fermentation was determined by subtracting the initial height from the actual height. * This process was continued for different glucose concentrations like %10,%15,%20 and %25 glucose solutions for 5 times for each. Anova: Single Factor SUMMARY Groups Count Sum Average Variance %5 glucose concentration 5 6,8 1,36 0,018 %10 glucose concentration 5 11,6 2,32 0,032 %15 glucose concentration 5 16,8 3,36 0,043 %20 ...read more.


Examples for Calculations of Statics; Mean= a+b+c+d+e/5 (1,5+1,3+1,5+1,2+1,3)/5 =1,36 Variance= a-mean=x b-mean=y c-mean=z d-mean=t e-mean=u Variance=x�+y�+z�+t�+u�/(n-1) example; 1,5-1,36=0,14 1,5-1,36=0,14 1,3-1,36=-0,06 1,3-1,36=-0,06 1,2-1,36=-0,16 n=5 Variance=(0,14)�+(0,14)�+(0,06)�+(0,06)�+(0,16)�/4=0,018 Standart deviation= =0,1341 Standart error= standart deviation/ = 0,06 the glucose concentrations used(%) 5 10 15 20 25 mean 1,36 2,32 3,36 4,22 5,26 std 0,134164 0,178885 0,207364 0,238747 0,296648 variance 0,018 0,032 0,043 0,057 0,088 se 0,06 0,08 0,092736 0,106771 0,132665 t 2,776445 2,776445 2,776445 2,776445 2,776445 %95 cl 0,166587 0,222116 0,257477 0,296443 0,368337 Table 3:The mean,standart deviation ,variance and standart error statics for each glucose concentration used.(%5,%10,%15,%20 and %25 glucose concentrations are used) Graph 1:The mean graph for CO2 gas produced in each different concentration of glucose solution used. CONCLUSION AND EVALUATION In this experiment the effect of different glucose concentrations on the rate of fermentation is observed.5 ml of %5,%10,%15,%20 and %25 glucose solutions are added to 15 ml water and 0,500 g yeast by order and heated. The test tubes are covered with parafilm so that the CO2 released by the fermentation won't be lost. The reason that the test tubes are heated because fermentation best occurs at 30C�. By the Anova test it is seen that the p-value 1,01E-16 < 0,05 so the hypothesis is accepted.Which shows that by changing the glucose concentration there will be a significant difference seen in the rate of fermentation . "The rate of fermentation will increase proportionally as concentration increase but it will eventually stop."(3) 3http://www.megaessays.com/viewpaper/61901.html ?? ?? ?? ?? 1 ...read more.

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