1. ICT In Biology
(TBC 3013)
Group members:
Yee Hon Kit D20091034822
Yee Chin Tien D20091034824
Ngang Huey Chi D20091034861
Sharifah roqaiyah D20091034851
3. Biological Principle:
In the absence of oxygen, yeast will undergo
anaerobic respiration. Yeast converts glucose
into ethanol and carbon dioxide. So, the carbon
dioxide given out reflect the rate of anaerobic
respiration.
Glucose was fermented because this sugar can
pass rapidly into the cell and enter directly into
metabolic pathways
4. ENGAGE
Can she keep diving under
the water after the diving
tank that stored compressed
gas such as oxygen have
depleted?
Some organism such as
bacteria can survive in
the absence of oxygen,
why?
Anaerobic respiration occurs in oxygen-
poor marsh muds.
6. Procedure:
1. 4 grams of yeast was measured by the electronic
balance.
2. Glucose solution was prepared in a beaker.
Different concentration of glucose solution was
prepared as follows:
5%, 10% and 15%
3. The glucose solution of 5% was boiled under the Bunsen
flame to evaporate any dissolve oxygen in the solution.
4. This glucose solution was cooled down by the ice to
prevent the heat produced killed the yeast during the
fermentation.
5. The carbon dioxide sensor was connected with the Data
Logger.
7. 6. Glucose solution was then mixed with the yeast in the reagent
bottle under the water bath with temperature 30 oC. Water
bath was prepared to maintain the temperature as heat
produced will affect the reaction during anaerobic respiration.
7. A layer of oil was added on the top of the solution to prevent
gas trapped in the solution.
8. The carbon dioxide sensor sealed the reagent bottle of the
mixed solution
9. The reagent bottle was put under the water bath for 10
minutes.
10. The amount of carbon dioxide was recorded at each 5 seconds
interval.
11. Steps 4 to 11 are repeated but the concentration of glucose
solution is changed to 10% and15% respectively.
16. Concentration
of glucose
Initial Final Rate of Respiration
(ppm/min)
5% 758.154 5960.923 212.73
10% 590.769 2924.308 122.45
15% 738.462 3042.462 96.72
From the graph and table, it is shown that the fermentation of
5% of glucose produced the highest amount of CO2 and highest
rate of fermentation. While fermentation of both 10% and 15%
of glucose have produced almost same amount of CO2 in the
same period of time, both also have steady rate of respiration.
17. Questions
1. Look at your table ,why does the carbon
dioxide level change?
2. Which fermentation of glucose produced
higher amount of carbon dioxide gas? Why?
3. What does the graph tell you about the
change in carbon dioxide level during
fermentation.
4. What is the end product of fermentation?
State the equation of yeast fermentation.
18. Answer
1. The change of carbon dioxide level indicated that the yeast fermentation of
glucose have begun. Or anaerobic respiration has initiated by yeast.
2. In the same period of time, fermentation of yeast in glucose 5% have
produced higher amount of carbon dioxide. This can be explain as in high
concentration of glucose such as 10% and 15%, the increase in glucose
concentration led to in the increase in fermentation time. Besides, when
the glucose content increased, the glucose uptake rate decreased, this will
affect the rate of fermentation. Thus, as longer time is required for
fermentation of yeast to occur, it have reduced the amount of CO2
produced for both 10% and 15% of glucose fermentation.
3. Fermentation of different concentration of glucose will have different rate
of fermentation and different amount of end product in fixed time.
4. Ethanol, carbon dioxide and energy. C6H12O6 --------------> 2C2H5OH + 2CO2 +
2ATP
19. Discussion
1. The fermentation of glucose, which occurs primarily
when the glucose concentration is high or when oxygen
is not available.
2. The cells have a low energy yield of only about 2 ATP
per mole of glucose metabolized. The stoichiometry of
this reaction is
C6H12O6 --------------> 2C2H5OH + 2CO2 + 2ATP
where represents chemical energy utilized in the growth
processes.
20. 3. The influence of different glucose concentration on metabolic
activities of yeast was evaluated by the overall amount of C02
and rate of reaction.
4. In high concentration of glucose such as 10% and 15%, the
increase in glucose concentration led to in the increase in
fermentation time.
5. Besides, when the glucose content increased, the glucose
uptake rate decreased, this will affect the rate of
fermentation.
6. Thus, as longer time is required for fermentation of yeast to
occur, it have reduced the amount of CO2 produced for both
10% and 15% of glucose fermentation.
7. Conversely, for the same reason which mentioned above,
fermentation of 5% glucose have produced the higher amount
of CO2 and with the highest rate of fermentation.
21. ENHANCE
Give another example aside from the given
picture of fermented food and
discuss the making of this fermented food.
22. Unique Feature of This Activity
1. Amounts of carbon dioxide produced can be detected
and measured accurately (measured in every 10 seconds).
2. It is impossible to measure the amount of carbon dioxide
accurately using conventional method.
3. Less work need to be done by the students. The
experiment can be carried out for a longer period of time
and the results will be recorded automatically during that
period of time.
4. The pattern of amount of CO2 production changes can be
observe along with the experiment.