An Experiment to Find Out the Effect of Osmosis on Potato Cells

An Experiment to Find Out the Effect of Osmosis on Potato Cells

Plan

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Apparatus:

· A borer

· 25 test tubes

· 5 test tube racks

· 2 potatoes

· A ruler

· A sharp knife

Variables: Four different sugar solutions at 10%,20%,30%and40% and

distilled water

Hypothesis: I hypothesis that the higher the sugar the less the potato

size will increase. I think this because I think it will be harder for

the liquid to get in because it is denser.

Using the borer make cuts into the potato and pull out the pieces of

potato. Chop the pieces so they are 20mm long repeat process 25 times.

This experiment must be statistically viable i.e. the potato pieces

must be identical. If you come to a bad piece of potato discard it.

Put all the pieces into individual test tubes. Using one of the

solutions fill up 5 test tubes to exactly the same height. Repeat

process for all the solutions. Put test tubes into racks and leave for

24 hours. This should be done as quickly as possible to ensure each

piece of potato is immersed for exactly the same period of time.

Research

[IMAGE]Fig 1

Osmosis is the transfer of a liquid solvent through a semi permeable

membrane that does not allow dissolved solids (solutes) to pass.

Osmosis refers only to transfer of solvent; transfer of solute is

called dialysis . In either case the direction of transfer is from the

area of higher concentration of the material transferred to the area

of lower concentration. This spontaneous migration of a material from

a region of higher concentration to a region of lower concentration is

called diffusion. Osmosis will occur if a vessel is separated into two

compartments by a semi permeable membrane, both compartments are

filled to the same level with a solvent, and solute is added to one

side. The level of the liquid on the side containing the solute will