Investigating osmosis - coursework for biology includes prediction evaluation and results
Prediction
Osmosis is defined as ¡§the movement of water molecules across a partially permeable membrane from a region of high water concentration to a region of low water concentration¡¨.
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 are equal (have reached equilibrium).
Knowing that osmosis will occur across a semi-permeable membrane whenever there is a difference between the water concentrations on the two sides of the membrane, and knowing that when this happens to cells they will either become turgid if water flows into them, or plasmolysed if water flows out of them, and thus change their volume, we want to test the hypothesis that:
If the concentration of a solution into which a cylinder of potato is placed is greater than a certain level the cylinder will contract, and if the concentration is less than that level it will expand. This can be seen in living cells. The cell membrane in cells is semi-permeable and the vacuole contains a sugar/salt solution. So when a cell is placed in distilled water (high water concentration) water will move across the semi-permeable membrane into the cell (lower water concentration) by osmosis, making the cell swell. This cell is now referred to as turgid. If done with potato cells the cells would increase in length volume and mass because of the extra water. If these potato cells were placed in a solution with a low water...
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Osmosis Coursework
... decision to leave the strips in the sucrose solution for 24hours to ensure that the process of osmosis is fully completed. Hypothesis: I predict that when placed in a solution of high sucrose concentration the potato strips will lose water due ... mass, and when placed in a low sucrose concentration they will take in water due to osmosis and therefore increase in mass. I also predict that there will be a point of equilibrium where the potato strip neither loses nor gains ...
Investigating the concentration of Glucose inside Cell sap in potatoes Through Osmosis.
... into the more concentrated area, causing the potato sample to lose weight. This means that my prediction, using information I have learned from studying Osmosis, was in fact correct. Test Data - Make Line Of Best Fit Chart - Glucose Concentration along the ... glucose solution. I predict, that the stronger the solution of glucose, the more weight the piece of potato will lose, and when placed in a more dilute glucose solution, the potato will gain weight. This is due to Osmosis, the movement ...
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... investigation. I will use 0% , 4% , 8% , 12% and 20%. Prediction I predict that when I increase the concentration of the sugar solution ... to the concentrated solution. The factors that have an affect on osmosis  Concentration of the sugar solution  Concentration of the potato cell ...
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... even more accurate results. To get more evidence to support my prediction I could try different concentrations of glucose solution, for example I could ... this will matter because although I don't know whether temperature affects osmosis, the experiment will only take place once, and all the specimen ...
Biology investigation osmosis
... cell, making the cell lose its shape and weight and the cell becomes flaccid. Turgid- Flaccid- Prediction Due to my background knowledge of Osmosis I predict that the chips place in the more dilute solutions than others will gain the most ... .78g Analysis of results The end results did not turn out as expected and the graph was not shaped as predicted. There are a number of reasons why this may have happened, such as, the concentration of the sugar solution or ...