SAPS Water Potential of a Potato Cell - student notes Osmotic potential of plant cells is a key part of understanding cellular processes. Here we present two methods of determining osmotic potential of plant tissues using potatoes.
The standard protocol for measuring weight change of tissues in varying osmotic solutions is reliable but do not demonstrate the changing solute potentials.
We also present a protocol that is slighly more challenging, but far more visual, the Chardakov method. Here students can observer changing solute potentials, by observing the resulting density change in sugar solutions in which potato tissue has been immersed. A coloured extract of the bathing solution can be seen to fall, rise or disperse when added to a known molar sugar solution.
This could be attempted as an individual investigation, or could be presented to the class as a demonstration with flex / web cams on the whiteboard.