Osmosis in Potatoes

Osmosis in Potatoes

My main aim in this experiment is to find out if osmosis occurs in a

potato, and how it affect the potato in different molar solutions of

sucrose and water, and finally the approximate morality of the potato.

Apparatus

· Stop Clock - to time our experiment

· Cutting tile - to cut the potato on

· Knife - to cut the potato

· Measuring flask - to measure the solutions

· Six beakers - to do the experiment in

· Distilled water - part of the experiment

· Sucrose - part of the experiment

· Potatoes - part of the experiment

· Tissue paper - to dry the potatoes after the osmosis takes place

· Balance - to weigh the potatoes

· Cork borer - to cut out potato cylinders

Hypothesis

Osmosis is the net movement of water particles through a

semi-permeable membrane from an area of high concentration to an area

of low concentration. Water particles in a sugar solution are less

concentrated than pure water as the larger sugar molecules spread them

out. Particles diffuse both ways through the membrane, but the net

movement will always follow the concentration gradient. Net movement

will not occur between equal concentrations of solutions. Larger

molecules e.g. glucose cannot diffuse through the membrane.

The potato, when cut up into pieces, will need water and light to

survive. With both of these sources the potato will keep on working,

until it dies of either lack of water, too much water.

Potatoes produce sugars by photosynthesis. If a potato is placed in a

solution stronger than it's own internal glucose solution, water will

diffuse out and it will shrink, as the water molecules outside will be

less dense as they are more spaced out by the sugar molecules. It will

continue to shrink until the concentrations are equal. Similarly if a

potato is placed in a weaker solution it will have the opposite

effects.

Prediction

As the potato (hopefully) contains glucose the distilled water is more