Osmosis - Diffusion through cell membranes

When it rains, ripe cherries often burst. If you want to make radishes crisp again or straighten wilted flowers again, you put them in water.
To preserve foods, fish, for example, it is rubbed with salt; cucumber or cream cheese can be placed in salt solutions.
What do these events have in common and how do they differ?
In the following experiment you will treat a thin slice of potato and two potato cylinders with different amounts of salt. Based on the observed changes you will then find explanations for the events and issues described above.                               more see below

 

Experiment

1.      Carve from the potatoes two equal cylinders, small enough to fit into the infusion bottles.

2.      Place one potato cylinder into a bottle with water and the other into a bottle with concentrated salt solution.

3.      Cap the bottles and observe the changes at regular intervals.

4.    Keep the containers for several days and check again the appearance of the cylinder.

Tasks

1.      Write down your observations.

2.      What influence does the salt have on the potato slices? Based on this answer, try to explain the changes in the inserted potato cylinders

3.      The term "osmosis" is generally discussed at the particle level. Explain the process with the help of a drawing.

4.      Now explain the real-life examples with the cherries, radishes and flowers. Also, answer the question in the introduction.

 

First published: 28.12.2013                                                                 Last modification: 15.05.2014