HKTA The Yuen Yuen Institute No'2 Secondary School

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HKTA The Yuen Yuen Institute No.2 Secondary
School Biology Project (2002/2003)
Analysis of Different Brands of Washing Powder
Kwok Wai Sze 6S (6) Lo Wai Hing 6S (15)
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Table of contents pages
Introduction ------------------------------------
--------------P.1 Outline of the project contents
----------------------------P.2 Aim
--------------------------------------------------
----------- P.3 Project plan ---------------------
------------------------------ P.4 Content -
hypothesis --------------------------------------
--P.5 - Design of experiment
----------------------------P.6-P.8
- Materials and apparatus -----------------------
P.9-P.10 - Procedures
---------------------------------------- P.11-14
- Results ---------------------------
------------------ P.15-P.17 Discussion -
Explanation of results -----------------------
P.18-P.21 - Limitations and
errors ---------------------- P.22
- Suggestions for improvements
-------------P.23 - Conclusion
--------------------------------------P.24 Alterna
tive test for protease in washing powder
--------P.25 Design your own washing powder
-------------- -----------P.26 Innovation
--------------------------------------------------
-----P.27-P.29 Review of the project
-----------------------------------------P.30-P.31
Overall comments --------------------------------
- ------------P.32

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Introduction
Most manufacturers of washing powder claim that
their product contains enzymes, like lipase and
protease, which can remove any stubborn stains.
It is interesting to find out whether they are
only paying lip-service or really contain these
two enzymes, and to compare their washing power
among different brands of washing powder.Thus, an
experiment was designed.
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Outline Of The Project
Choosing a topic for the project
Making a project plan
Conducting the experiment
Discussion and review
Report Writing for the presentation of the
project
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Aim
To see whether all the commercial
washing powder chosen containing the two enzymes
or not. To identify which brands of washing
powder containing which kind of enzymes. To
compare the washing power between different
brands of biological washing powder.
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Hypothesis

• If the egg white and fatty-stain in these
  experiment decrease in size, it indicate that
  protease and lipase are presence in washing
  powder.

• If the decreases in rate of different egg white
  and fatty-stain soaked in different washing
  powder is different, the amount of protease and
  lipase functioning in different washing powder is
  different. Then, we can draw a comparison between
  the effectiveness of different washing powder.

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Design of experiment
In this experiment, 6 pieces of egg whites and
cloth with lipid-stains are allowed to be soaked
in a beaker of 6 different solution of washing
powder in a water bath that kept at 30?
respectively for enzyme reaction. After 30
minutes, the size of the egg whites and
lipid-stains treated with different washing
powder are observed and compared among each other
as well. The smaller the size of the egg white
and the lipid-stain, the higher the washing power
of the washing powder. And it is assumed that all
the enzymes work in favorable condition.
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Control
using distilled water only to replace the
solution of washing powder.
In order to prove the decrease in sizes of egg
whites and lipid-stains is only due to the
digestion of protein and lipid by the enzymes in
the washing powder
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Independent variable Types of washing powder
Dependent variable change in sizes of egg whites
and fatty-stains
Controlled variables temperature, volume of oil,
egg white and water, mass of washing powder,
sizes of cloth, time
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Materials and apparatus
250 ml beaker 7
A 100 ml beaker
7 cooked eggs
A measuring cylinder
Thermometer 1
100 cm3 oil
An electronic balance
Distilled water
A razor blade
A weighing bottle
A white tile
9 cm 9 cm cloth 7

1 cm 1 cm egg white 7
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Washing powder used
Attack
White Cat
Beauty Powder
Lion Top
Liby
Fab
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Procedures
Preparation of materials
Egg white 1) Seven eggs were boiled for 10
minutes. 2) The shells and the yolks of the
cooked eggs were removed. 3) Seven pieces of 1cm3
egg white were cut with a razor blade.
Fatty-stain 1) Seven 9cm 9cm cloths were
cut. 2) 50 cm3 oil were poured into a 100ml
beaker. 3) Seven cloths were soaked in the beaker
respectively. 4) Seven cloths stained with oil
were dried with a hair dryer.(To prevent oil drop
down and mix with the external solution.
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Solution of washing powder 1) 0.80g of each
brand of washing powder were weighted by the use
of electronic balance. 2) The weighted washing
powder were dissolved with 100cm3 tap water in
six different 250cm3 beaker respectively . 3) 100
cm3 distilled water were added to a 250cm3 beaker
to act as control. This is used to prove the
decrease in sizes of egg whites and lipid-stains
is only due to the digestion of protein and lipid
by the enzymes in the washing powder. 4)
Different beakers were labeled.
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Test for protease
1) Seven 1cm3 egg white were added to
corresponding beakers that contains different
washing powder solution or distilled water.
2) Seven beakers were placed in the water bath
that kept in 30 ?
3) After 25 min, Seven egg whites were removed.
4) seven egg whites were dried with tissue paper.
5) 15cm3 tap water were added to seven 25cm3
measuring cylinder respectively.
6) Seven egg whites were placed in corresponding
measuring cylinder respectively.
7) The readings were recorded.
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Test for protease
1) Put a piece of cloth stained with fatty-stain
into seven beaker contain different testing
solution respectively.
2) Seven beakers were placed in the water bath
that kept in 30 ?
3) After 15 min,seven a pieces of cloth were
removed from the beakers respectively.
4) All cloths were allowed to dried for one day.
5) The size of the fatty-stain were compared.
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Results
Table a comparison of different properties from
different washing powder.
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Table The change in volume of egg white after
soaking in different testing solution.
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Table the relative size of the fatty-stain on
cloths after soaking in different testing
solution.
Key refer to the larger size of the
fatty-stain on cloth refer to the
smallest size of the fatty-stain on cloth
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Discussion-Explanation of results
Test for protease
The result show that all egg whites have
increased in size but not decreased in size that
we expected.
Theoretically, if the washing powder that we
tested contain protease, the size of egg white
will decrease because protease had digested
protein in egg white.Then we can draw a
comparison from the result.
In the real situation, when we soaked the egg
white with the testing solution, external
solution enter the egg white and causing increase
in volume of egg white.
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The result show that egg white soaked in tap
water increased in 0.7cm3 in volume. So we take
0.7cm3 as a standard that egg white will
increased 0.7cm3 in volume when soaked in testing
solution. i.e. for those egg white that increased
in volume less than 0.7cm3, digestion of protein
occurs.
To find out which washing powder are more
effective in digesting protein, we can compare
the decrease in volume of egg white after
increased in 0.7cm3. The egg white that show the
largest decrease in volume, the most effective in
digestion of protein that the corresponding
washing powder is.
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It was show that all washing powder contain
protease. And the effectiveness of different
washing powder in removing protein-stain in
descending order is
Attack
Lion Top, Fab, Beauty Powder
White Cat
Liby
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Test for lipase
The result show that all cloths stained with oil
have decrease in size.
The decrease in size of the fatty-stain was
mainly due to the presence of enzyme in washing
powder. Manufacturers of washing powder add
lipase to remove fatty-stain on cloths. Lipase is
a kind of enzyme that can digest lipid and
causing decrease in size of fatty-stain on
clothes in this experiment.
Lion Top
Attack
Fab
Beauty Powder
Liby
White Cat
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Limitations and Errors
It is very difficult to keep the sizes and volume
of different egg white identical.
It is not obvious to observe the permanent spot
in the test for lipase.
Not all washing powder were dissolved in tap
water.
Solution enter different egg white may not be the
same.
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Suggestions for improvment
Use more concentrated washing powder solution.
Increase the time for the enzymatic reaction.
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Conclusion
Attack, Beauty Powder, Fab, White Cat, Lion Top
and Liby contains protease and lipase that can
digest protein and lipid.
The effectiveness of washing powder in removing
protein-stain in descending order is Attack, Lion
Top,Fab, Beauty Powder, White Cat and Liby.
The effectiveness of washing powder in removing
fatty-stain in descending order is White Cat,
Liby, Beauty powder, Fab, Attack and Lion Top.
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Project Plan
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Alternative test for protease in washing powder

• Prepare the solution of washing powder with the
  same steps as the original one.
• Add strips of photographic film about 4 mm wide
  to each beaker of washing powder solution.
• Incubate in a water bath at 50C - 60C for 10
  20 minutes, or until the film has cleared.
• Record the time taken to completely clear the
  photographic film.
• (A suitable control experiment should be carry
  out using water alone)

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Innovations
Medical treatment of thromboses Thromboses are
the blood clots that sometimes build up in
damaged blood vessels. However, in some cases,
they might occurs abnormally and block an artery
in the heart or the brain, resulting in a heart
attack or a stroke. Blood clots can be digested
away by certain protease which dissolve insoluble
fibrin, from which the clot is built up.
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Medical treatment of atherosclerosis Cholesterol
is a kind of lipid which can be carried in the
blood plasma in form of lipoproteins. The balance
of these lipoproteins is usually maintained by
special receptors in the livers cells but
saturated fats in the diet decrease the activity
and hence lead to a rise in plasma cholesterol.
The deposit of cholesterol can cause thickening
of artery walls arteriosclerosis). This may block
artery in the heart or the brain, resulting in a
heart attack or a stroke. Based on the same
principle as thrombosis, lipase can be introduced
to the bloodstream so as to digest the
cholesterol.
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Fruit juice production During the manufacture of
fruit juice the cells of the fruits have to be
broken down before the bulk of the juice can be
extracted. Plant cell walls are built of
cellulose fibres which are held together by
pectins and hemicelluloses, and they are
extremely tough. If very high temperatures are
used to break down fruit tissues, this will
affect the colour and flavour of the juice.
Instead, the fruit is crushed, and enzyme
preparations containing cellulases,
hemicellulases and pectinases are added. These
cause the cell walls to break up and most of the
liquid is released.

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Review of the project
By Lo Wai Hing In this project, we have gained
both the failure and success. The failure, of
course, is due to our negligence and impatience.
Nevertheless, we did not give up. After our
review and improvement, we conducted the
experiment again. Luckily, the experiment was
succeeded eventually. Through this process, I
realized the importance of imperturbabilitymore
haste, more speed certainly, the co-operation
between group members are also very essential.
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By Kwok Wai Sze This project increase our
interest in biology. when doing this project, we
came across a lot of problems.Through solving
this problems, my problems-solving skills is
enhanced. Doing the presentation myself boost my
confident to speak. So, this project is very
meaningful.
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Overall comments
In general, the project was very successful even
though we had failed to accomplish our aims in
the both sections of the experiment at the first
time because we had tried our bests to improve
and the experiment was succeeded finally under
our effort. The most important thing is that we
had learnt from mistakes. Actually, there are
still a lot of things that can be improved.
Firstly, we can find more information concerning
this topic from the Internet or newspaper
cuttings before our experiment secondly, we can
better prepare the materials used beforehand
thirdly, we have to consider everything related
to the experiment to minimize any experimental
errors, etc.
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Frankly speaking, this kind of project is very
advantageous and beneficial to us. It not only
cultivates our interests in scientific
investigation, but it also provides a special
channel for us to learn in an interest way. In
the course of cooperation in carrying out the
projects, we can familiarize ourselves with our
fellow group mates. Essential social skills like
effective communication, time management and
interpersonal skills can be learnt through the
process.
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Reference Web Sites

• http//www.schoolscience.co.uk/content/index.asp
  
• http//www.ncbe.reading.ac.hk
• http//cccmkc.edu.hk/kei-kph/index.thm
• http//resources.ed.gov.hk/biology/english/index
  .html