Osmosis Investigation

Osmosis Investigation

Aim:The aim of this investigation is to explore osmosis in potato

cells and find approximately the concentration of sucrose within

potato cells by measuring the change in mass of potato chips when

immersed in different sucrose solutions for a set period of time

Introduction: Osmosis happens in the cells of all living things. It is

a simple process where water molecules diffuse from one cell to

another through the partially permeable cell membrane. (the membrane

has tiny holes in it that allow simple molecules, such as water, to

pass through) During the process of osmosis, water moves between

higher and lower concentrated solutions of either saline or a sugar

solution until water molecules are evenly distributed between the two

(or more) solutions (until they reach equilibrium), and in the case of

cells, when the cells are of equal dilution. This movement of water is

called diffusion.

In the example below, there are two unbalanced solutions separated by

a partially permeable membrane. Solution A has a higher concentration

of sugar molecules than Solution B.

As the process of osmosis begins, the water molecules from solution B

begin to move into solution A, seen below.

After time, enough water molecules have moved to achieve equilibrium,

and the process stops.

In this case the molecules are not of equal number. This means that,

if solution B was a cell, then it would of lost molecules and become

shrivelled, or flaccid, and cell A would of gained molecules and

become swollen, or turgid. This side effect can lead to cells either

dying from the lack of water in them or swelling to the extent that

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12. Carefully remove the chip with the tongs, remove any excess

moisture with a soft tissue and measure the mass with the top pan

balance. Record the result.

13. Repeat experiment 3 times to check your findings.

This preliminary experiment would determine whether or not osmosis is

reversible and a full investigation into this matter could then be

performed.

Other than those things, not much else could be changed, as the

results were very reliable due to the extensive precautions taken to

make it a fair test. In the future yet more experiments could be

performed to learn more about osmosis, such as seeing how time affects

osmosis or how surface area exposed to solution affects rate of

osmosis. Also, different vegetables could be used to examine

variations in sucrose concentration in different species.