Osmosis in Potatoes
Aim:
My aim in this experiment is to find out if osmosis occurs in a
potato, and how it will affect the potato in different molar solutions
of sucrose and water. Using the same size potato.
Theory:
Osmosis is the passage of water molecules from a weaker solution into
a stronger solution, through a partially permeable membrane. The tiny
holes in the membrane of the potatoes will allow the water molecules
to pass through in and out of the solution and the potato, depending
on the concentration gradient of the two substances. So in this case,
when the water concentration is lower than the potato , the sucrose
will go inside the potato, and the potato will gain weight. If there
is a higher concentration of sucrose in the potato, the sucrose should
leave again.
So it think that 0.2m will have the most weight loss because the is
less sucrose to get through the potato.
Apparatus:
Cutting tile - to cut the potato on
Knife - to cut the potato
Measuring cylinder - to measure the solutions
sucrose - part of the experiment
water - part of the experiment
Potatoes - part of the experiment
Fair test:
To make this experiment a fair test I am going to use the exact same
size potato pieces and the same amounts of solution But I believe one
of the most important step in the fair testing is to make sure that
the potato is fully covered by the solution. This is because the
potato should fully submerge, by having total contact with the
solution.
whether its Sucrose or Water, also I will do all 12 solutions at the
same with two of each solution (e.g. 0.2m) and take them out 72 hours
later so they all have the same length of time in the solution. Then
also I will repeat the experiment and find an average out of the
length and weight of the potatoes.
The results of this experiment are shown in the compiled student data in Table 1 below.
Keeping all of these the same will ensure that it is a fair test. The equipment I will be using during this experiment will be: § Bunsen Burner § Tripod § Jelly
through the visking tube with salt in. As in the visking tube it has a
To make the test fair I will use the same amount of water and the leaf
the same way as it does potato. I would also widen the range of sugar
The experiment was centered on the question: What is the concentration of sugar in a potato? This question is an important one to understanding how we digest potatoes and could be used for nutritional information. In order to find the answer to this question we cut a potato into 5 pieces, placing each in a different solution of sugar and water of about 150ml. Then we waited 30 minutes to see if the effects were hypotonic or hypertonic, giving us a reasonable percentage to how much sugar a potato has naturally. We predicted that the solutions with 0%, 1% and 5% sugar would create a hypotonic environment, increasing the weight of the potato pieces. While the 10% and 15% solutions would create a hypertonic environment, causing the potato to lose weight. This assumes that a potato is naturally between 5% and 10% sugar.
there would be no flow of water into or out of the cell so the cell
were not kept the same then it would not be a fair test, for example
When I am not using them I will place them away from my experiment and
If I keep all of these the same my experiment will be a fair one.
Experiment to Investigate Osmosis in Potatoes The aim of this experiment is to investigate the movement of water in and out of plant cells. The cells chosen for study will be taken from potato tubers. Firstly I will explain what osmosis is. Osmosis is the passage of water from a region of high water concentration through a semi permeable membrane to a region of low water concentration. This definition contains three important statements: a)
* Size of potatoes * Diameter of each potato tube * Time in sugar solution We need to make sure in both experiments the fair test lists are used and the procedures are carried out. This needs to be done otherwise my results will not be accurate and will look odd. Method: Firstly we got out all our equipment.
water in the potato, then the water will go out of the potato and into
An Experiment to Investigate Osmosis in Plant Tissue. Aim: To conduct an investigation to compare the osmotic behavior of the osmotic animal. two types of plant tissue in varying concentrations of sucrose. solution. Then we can find the solution.
4. Put each group of potato discs in one of the 6 test tubes and watch