PowerPoint presentation 5 · Movement of water in and out of cells by osmosis. Background. How can...
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Transcript of PowerPoint presentation 5 · Movement of water in and out of cells by osmosis. Background. How can...
How can we determine the water potential of
potato tissues?
Potato
1.0 M Sucrose solution
(= 342 g sucrose in 1 L of solution)
Procedure (2)
Cut potato cylinders into length of 5 cm.
Blot dry the potato cylinders and put them into a Petri dish.
Procedure (3)
Immerse 2 potato cylinders in
each tube that contains different
concentration of sucrose
solution.
After 40 mins, take out the
potato cylinders, blot dry and
measure the length of the potato
cylinders.
Result Table
� 1. Tabulated result : � Notice the position of independent variable,
dependent variable in the table.
� Units and suitable conversions should be shown clearly and correctly
� Title of the table should be written correctly according to the aim of the experiment.
e.g. Effect of sucrose concentration on thee.g. Effect of sucrose concentration on the
length of potato cylinderlength of potato cylinder.
Effect of sucrose concentration on the percentage
change in length of potato cylinder
- 3.04.854.84.950.6
- 1.04.954.95.0 50.4
- 5.04.754.74.850.8
4.6
5.1
5.2
- 7.04.654.751.0
+ 3.05.155.2 50.2
+ 5.05.25 5.3 50
% change in % change in
length of potato length of potato
cylinderscylinders
Average Average
ffinal length inal length
of potato of potato
cylinders cylinders
(cm)(cm)
FFinal length inal length
of potato of potato
cylinders cylinders
(cm)(cm)
OOriginal riginal
length of length of
potato potato
cylinders cylinders
(cm)(cm)
concentration concentration
of sucrose of sucrose
solutionnsolutionn / M)/ M)
Key : + increase in lengthKey : + increase in length
-- decrease in lengthdecrease in length
Graph
� Notice the choice of axes
x-axis – for independent variable (unit should be stated)
y-axis – for dependent variable (unit should be stated)
� Notice the rule of using short straight lines to join
the points or the smooth curve to join the points
� Title of graph should be added correctly and related
to the aim of the experiment
e.g. Effect of sucrose solution on the % change in length of potato
cylinders
Effect on sucrose concentration on the %Effect on sucrose concentration on the %Effect on sucrose concentration on the %Effect on sucrose concentration on the %
change in length of potato cylinderchange in length of potato cylinderchange in length of potato cylinderchange in length of potato cylinder
-8.0-8.0-8.0-8.0
-6.0-6.0-6.0-6.0
-4.0-4.0-4.0-4.0
-2.0-2.0-2.0-2.0
0.00.00.00.0
2.02.02.02.0
4.04.04.04.0
6.06.06.06.0
0000 0.20.20.20.2 0.40.40.40.4 0.60.60.60.6 0.80.80.80.8 1111 1.21.21.21.2
Concentration of sucrose solution / MConcentration of sucrose solution / MConcentration of sucrose solution / MConcentration of sucrose solution / M
% c
hange i
n l
ength
of
pota
to%
change i
n l
ength
of
pota
to%
change i
n l
ength
of
pota
to%
change i
n l
ength
of
pota
to
cyli
nders
cyli
nders
cyli
nders
cyli
nders
Laboratory Report
� Title
� Aims
� Theory/Background (optional)
� Apparatus
� Design of experiment
� Procedure
� Precautions and safety measures
� Results (including data and observations)
� Discussions (including possible sources of errors and improvements to be made)
� Conclusion
� Questions for further thought (optional)