Investigation to see how the Concentration of a Sugar Solution affects Osmosis in a Potato Chip.

Neeraj Bhardwaj

Investigation to see how the Concentration of a Sugar Solution affects Osmosis in a Potato Chip

Scientific Knowledge

Osmosis is a special type of diffusion. Osmosis is normally referred to the passage of water from a region of high water concentration through a semi – permeable membrane to a region of lower water concentration.

Solutions are normally passed through a partially permeable membrane in order to even out solutions and the process called osmosis does this. Semi-permeable membranes are very thin layers of material, which allow some things to pass through them but prevent other things from passing through. This is said to be partially permeable. The molecules that it allows to pass is due to the molecular size of that molecule, for example sugar molecules are too large to pass through the partially permeable membrane but on the other hand molecules such as water are small enough to diffuse through it. As the semi – permeable membrane only allows certain molecules through it also makes both solutions of even concentrations.

Osmosis is also interlinked with plant cells in order for the take up of water for the cells. When plant cells take up water via 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. Turgidity is very important to plants because this is what makes the green parts of the plant “stand up” into the sunlight. However, there is a downside for plants as osmosis can also give consequences. When plant cells are placed in concentrated sugar solutions they lose water by osmosis and they become flaccid, this is the exact opposite to turgid.

Osmosis is also related to water movement through plants in order for transpiration and photosynthesis to occur. Osmosis is taken place in the roots of the plants. As the roots of the plant have such a big surface area this increases the rate of transpiration and helps the plant for nutrients and water for photosynthesis. Water enters the plant through tiny root hairs by the process of osmosis because the root hairs contain a solution that is more concentrated than the water in the soil. As water enters, the root – hair contents become less concentrated as they are diluted with water. This causes water to pass from cell to cell by osmosis, moving inwards towards the centre of the root and the xylem vessels. This flow of water also carries dissolved mineral salts from the soil into the plant. This water is then sent up the plant in to the leaves for the process of photosynthesis. Photosynthesis is development of where plants make their food by water air and trapped energy from sunlight. If a plant did not absorb water via osmosis through root hairs then photosynthesis cannot take place. Osmosis is indeed very important to plants.

There are many factors that affect osmosis. Below are the two main factors that affect osmosis:

Temperature
Sugar Solutions

The temperature would affect osmosis because if you increase the temperature of the solution then the molecules will be reacting and moving quicker which will therefore increase the rate of osmosis. Alternatively if you were to decrease the temperature of the solution then the rate of osmosis will decrease as the molecules will not be moving around instead bonded with other molecules.

Different sugar solutions will affect osmosis, as sugars such as lactose, maltose and sucrose will all work differently with osmosis as some are one cell thick and some are larger in size. This will affect osmosis because no sugars will be able to diffuse through the partially permeable membrane. If sugar solutions with a higher concentration then the mass of the chip will decrease because osmosis is working its way into the chip from the solution outside it. However, a sugar solution with low concentration osmosis will be working the opposite direction and the mass of the potato chip will ...