Osmosis in a Potato

Equipment Needed

2 potatoes that are about the same size
1 knife
Sugar
1 dish of water

The Experiment

Boil one of the potatoes.

Slice the top and bottom off both potatoes and scoop out a hole in each, as shown in Fig 1.

Remove a complete circle of peel from the lower half of each potato (Fig 2).

Place a spoonful of sugar inside the hole in each potato.

Fill the dish with water.

Place the two potatoes in the dish so that they are standing up in the water (Fig 3).

Leave the potatoes alone for 24 hours.

After 24 hours, the hole in the raw potato will be full of water.

There will be no change in the boiled potato (Fig. 4)

How It Works

Osmosis is the process in which water diffuses through a membrane from an area with a low concentration of solution to an area with a high concentration.

In the live potato, osmosis takes place through the cell membranes.

The water moves from an area where there is a low concentration of solution (the dish), to an area where there is a high concentration of solution (the hole in the potato, which is full of sugar.)

The process of boiling destroys the cell membranes. Therefore, in the boiled potato, osmosis no longer takes place.