The Concentration of Sugar in the Cell Sap of a Potato Cell's Vacuole Plan
In this experiment I am intending to investigate the concentration of
sugar in the cell sap of a potato-cell's vacuole. I will discover this
using my knowledge of the biological process of Osmosis.
Osmosis is the movement of solvent (usually water) through a
semi-permeable membrane separating solutions of different
concentrations. The solvent passes from a more concentrated solution
to a less concentrated solution until the two concentrations are
Many cell membranes behave as semi-permeable membranes, and osmosis is
a vital mechanism in the transport of fluids in all living organisms,
the transport of water from the roots up the stems of plants is just
one of these.
[IMAGE]For this experiment I will need the following apparatus:
1. One large potato,
2. [IMAGE]Five glass beakers,
3. One measuring cylinder (50ml),
4. One potato corer,
5. [IMAGE]One dissection tile,
6. One scalpel,
7. One measuring scale (2dp)
8. [IMAGE]Ruler (1dp).
To discover the concentration of sugar in the cell sap I will place a
piece of potato, exactly 2.5cm in length, in a beaker of salt solution
(varying in strength) and leave it for 24 hours. If the piece of
potato increases in weight, the concentration of water in the solution
is too low, therein, if it decreases in weight the concentration of
water in the solution is too high. But if there is no change in weight
whatsoever then the concentration of water in the solution is
precisely equal to that of the cell sap.
Before beginning the actual experiment I must first mix the salt
solutions. As this investigation is to discover the concentration of
sugar in the cell sap I must first predict this and base my
concentration range around this. I have chosen the use the strengths
0%, 10%, 20%, 30% and 40%, I will pour exactly 50ml of each solution
into 3 glass beakers (15 in total) ready to begin the experiment.
1. [IMAGE][IMAGE]First use the potato corer to extract fifteen pieces
2. Cut each piece to 2.5cm in length.
3. Weigh each piece of potato and make a note of the results.
4. [IMAGE]Place one piece of potato in each beaker of solution.
5. Leave for 24 hours.
6. Remove each piece of potato from the solution.
7. Wipe of all excess liquid.
8. Re-weigh each piece of potato.
9. [IMAGE]Record the results.
Constants and Variables.
In this experiment there should only be two changing variables:
1. Different strengths of sugar solution.
2. Changing weight of the potato samples.
To be sure that these are the only variables I must:
1. Keep the potato...