• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

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

Extracts from this document...


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.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our International Baccalaureate Biology section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related International Baccalaureate Biology essays

  1. Marked by a teacher

    The Effect of Temperature on Enzymatic Activity. Aim To investigate enzyme activity ...

    3 star(s)

    Place the syringe into Beaker A (mouth facing up) and record the number of bubbles produced in 10, 15 and 20 minutes 5. 5. Fill Beaker B will 80 mL of water at room temperature (20�C) 6. 6. Fill 3cm3 of glucose solution into the syringe and then in

  2. The effect of the tempereature on yeast metabolism.

    Temperature/ oC �0.05 oC 30oC 40oC 50oC 60oC 70oC Mean rate of respiration % 2,00 5,50 17,83 30,50 24,83 b. processing data mean of 30oC= 0+0+5+5+10+0+5+5+10+10+0+0+0+0+10+0+0+0+0+0+0+0+0+0+0+0+0+0+0+0+=60/30=2 c. Graphs Attached on a graph paper. 4. Results/Conclusion a. Conclusion I have found that as the temperature increased, the rate of respiration of

  1. biology extended essay - How different diets: vegetarian, vegan and a meat centered diet ...

    Two to three times a year About twice a year Three to four times a year How many days are you absent from school when you have a cold/year? Once or twice Three to four times Almost all week I still go to school even when i am sick Almost all week How often do you exercise?

  2. The effect of toliet cleaning products on E-coli ...

    Effectiveness of cleaning product Dependent variable Whether the product has any effect or not shall be recorded. If the substance creates a zone of inhibition then the effect diameter shall be a lighter complexion then its surroundings. Diameter of zone of inhibition Depended variable The larger the diameter of the zone of inhibition the more effective the cleaning product.

  1. Yeast fermentation

    The more the fermentation, the more the carbon dioxide will be produced. Work cited: www.wikipedia.com Time Requirements This lab will require three, days to complete. Selecting variables Independent variables: amount of sugar Dependent variables: amount of CO2 produced Controlled variables Amount of yeast and water, the time for fermentation is

  2. Bread lab. What effect will the mass of glucose added to yeast have on ...

    Arrange the dough so that it is compressed enough so that the top of the dough is at 50 mL. 14) Place a damp cloth at the opening of the beaker. 15) Place the beaker in a 380C incubator and allow for it to rise for 30 minutes measured by a stop watch.

  1. Biology Internal Assessment - investigate whether the Window and Notching caterpillar share the same ...

    completely random it becomes more likely that we selected feeding sites that were easily visible on the leaves. This would have made it more likely for us to select the larger notches and windows as there were immediately more visible.

  2. How does changing the percentage of sucrose added to yeast affect the rate of ...

    third 5% sucrose trial where the froth achieved height of 38mm and thus a rate of 0.11mm/s. As this result is much greater than the other results it would have greatly increased the average. For example if we exclude that value for that experiment we get an average rate of 0.0505mm/s opposed to the calculated average for 5%sucrose of 0.062mm/s.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work