Many membranes allow all or none of the constituents of a solution to pass through; only a few allow a selective flow. As the potato is a plant cell, it contains a vacuole and a cytoplasm. The cell membrane is also partially permeable i.e. it lets some substances in but not all substances. This means that water paeticalscan diffuse into cells by osmosis if the cells are surrounded by a weak solution. (Osmosis is the movement of water molecules from a high area of water potential to an area of low water potential through a selectively permeable membrane.) If the cells ar!.
e surrounded by a stronger solution, e.g. salt water, the cells may loose water by osmosis.
To ensure safety , the boiling tubes will be kept in beakers so that they can not be knocked over. The potato chips will be cut on a white tile with a scalpel so that no one will be cut. Also while using scalpels everyone will have to wear safety goggles.
My experiment is not experimenting the how permeable the membranes are, but it is testing the rate of osmosis with different solutions. We also know that diffusion of water will occur from a lower concentration of solute to a higher concentration of solute. I am saying that the higher the concentration that the potato chip is exposed to, the more water will move out of it making it flaccid. Here are some diagrams to help explain.
Distilled water Salt solution (0.25m).
Potato Chip Potato chip.
Water has a lower Water moves out, from .
concentration than lower to higher con-.
potato chip, therefore centration.
water moves into chip .
and it becomes turgid.
The graph above is my prediction graph. This is how I think my final results will fit into a graph. As you can see, the change in mass for distilled water is positive (y-axis measures % gain/loss in mass), and all the rest are negative, below the x-axis, and the best fit line is a curve, showing that the loss/gain in mass is not proportional to the concentration of the fluid.
