The Effect of Placing Pieces of Potato in a Sucrose Solution

The Effect of Placing Pieces of Potato in a Sucrose Solution

[IMAGE]Osmosis

Osmosis

What is osmosis? If two solutions of different concentration are

separated by a semi-permeable membrane which is permeable to the

smaller solvent molecules but not to the larger solute molecules, then

the solvent will tend to diffuse across the membrane from the less

concentrated to the more concentrated solution. This process is called

osmosis.

Osmosis is of great importance in biological processes where the

solvent is water. The transport of water and other molecules across

biological membranes is essential to many processes in living

organisms. The energy which drives the process is usually discussed in

terms of osmotic pressure.

[IMAGE]

I have devised an experiment using osmosis;

Aim:

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To investigate the effect of placing pieces of potatoe in a given

strength of sucrose solution.

Prediction:

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I predict that, as the solution becomes more concentrated the more the

potatoe cells will shrink, as the water, of higher concentration

inside the potatoe cells, flows down a concentration gradient into the

solution, which has a lower concentration of water molecules.

Variables Description: Constant Variables:

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These stay the same all the way through the experiment and are the

fair test rules. In this experiment they are that the amount of

sucrose solution used must always me 40.0ml. This is to be placed into

the Petri dish. The solution needs to always be at the same

temperature. I will make sure that all experiments are at 20 degrees

centigrade before I start the experiment. I also need to make sure

that the potatoe is left in the sucrose solution for the same time, 30

minutes.

Equipment:

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* Potatoe

* Sucrose Solution (Strengths of 0.2M, 0.4M, 0.6M and 0.8M)

* Measuring Cylinders

* Petri dish

* Cutting Board

* Scales accurate to 2.