Osmosis
Aim
The aim of the practical was to find incipient plasmolysis using potato discs.
Apparatus
Large potatoes- this was the sample I was using.
- Molar solution- this was used to see when incipient plasmolysis takes place.
Cork borer- this was used to provide consistency between the size of the potato discs.
Petri dishes- to place the potato discs into.
Filter paper- so the potato discs are dry before weighing otherwise the potato discs would weigh more than they should do.
Razor blade- to cut the blocks of jelly up as accurate as possible.
Stopwatches- To time 15 minutes when I would weigh the discs again.
Method
- From the 1m solution prepare the same volume of five different concentrations of sucrose solution.
- I will use the cork borer to take cylinders of tissue from the same potato. And place them in a poly bag to avoid drying.
- I will place the cylinders of potato on a white tile and use a razor blade to cut 1mm disc. I will have 10 discs for each petri dish and five petri dishes.
- I will label the five petri dishes with their concentrations. And put in the solution.
- On dry pieces of filter paper I will weigh the five batches of 10 discs and record the masses in a table.
- I will put one batch into each solution and make sure they are immersed.
- I will leave the samples for 15 minutes.
- I will remove the discs from the solution and gently mop off any excess solution.
- I will put each batch onto dry filter paper and re weigh.
- I will record the results and work out the percentage change of the mass.
