How Osmosis affects Potato chips in Different Concentrations

How Osmosis affects Potato chips in Different Concentrations

Background: Osmosis is the movement of water molecules across a

partially permeable membrane from a region high water concentration to

low water concentration. A partially permeable membrane is a membrane

with tiny holes in so small that only water molecules can pass

through.

When you place a potato chip in a salt or sugar solution, then if the

potato has higher water potential some of the water will diffuse into

the Sal solution which will cause the chip to lose weight. However the

water amount is in the salt solution is larger then the water will be

diffused to the potato chip thus causing the chip to gain weight. If

the water amount is equal then the weight of the chip will not change.

In a high concentration of water the amount of solute (e.g. sugar) is

low. This could be called a weak or dilute solution. In a low

concentration of water the amount of solute (e.g. sucrose) is high.

This could be called a strong or concentrated solution. When two such

solutions are divided by a semi-permeable membrane the water will move

from the area of high concentration to the area of low concentration,

until both sides have reached equilibrium.

Plant cells always have a strong cell wall surrounding them. When they

take up water by osmosis they start to swell, but the cell wall

prevents them from bursting. Plant cells become "turgid" when they are

put in dilute solutions. Turgid means swollen and hard. The pressure

inside the cell rises and eventually the internal pressure of the cell

is so high that no more water can enter the cell. This liquid or

hydrostatic pressure works against osmosis. Turgidity is very

important to plants because this is what make the green parts of the

plant "stand up" into the sunlight. When plant cells are placed in

concentrated sugar solutions they lose water by osmosis and they

become "flaccid." This is the exact opposite of "turgid". The contents

of the potato cells shrink and pull away from the cell wall.