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Osmosis Investigation

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Valentine Macau Osmosis Investigation INTRODUCTION: Diffusion is the movement of particles from an area of higher concentration to an area of lower concentration. Diffusion results because of the random movement of particles. The diffusion of water into and out of a selectively permeable membrane is called osmosis. Because of the selectively permeable membrane, nothing but water and other very small particles can be diffused through osmosis. The cell membrane is similar to the membrane mentioned above, so the cell would lose water because of osmosis if it were placed in an environment in which water concentration is greater than that of the cell. A solution is isotonic if the concentration of dissolved substances is the same as the concentration inside the cell. Osmosis does not occur in an isotonic solution. A hypotonic solution is a solution in which the concentration of dissolved substances is lower than the concentration inside the cell. If a cell were put in a hypotonic solution, osmosis will cause water to move through the cell membrane into the cell. A solution is hypertonic if its concentration of dissolved substances is greater than the concentration inside the cell. If a cell were placed in a hypertonic solution, it would lose water. ...read more.


The more concentrated sugar solution fills up with water molecules which act in an attempt to dilute it, until there is the concentration on both sides of the membrane. Equipment Apparatus: Sugar solutions : Distilled water - 0.0M solution 2m Solution. Paper Towels Scalpel Cork Borer 1 large potato cut out each 6 potato chips to an equal circumference using the cork borer and use the scalpel to cut each piece into a 4cm chip and place them into the pure water. Remember to dry the chips first on the paper towel so that It does not affect the rate of osmosis. Method The method in which the experiment was done was that we cut the pieces of the potato with a scalpel then to 25mm then put them in a glass jar with a sugar solution of 0m and then done the same but put the other 3 pieces in a sugar solution of 2m. Remember to put sticky labels on each of the jars so we know which one had which solution in it. We then left the pieces of potatoes for 24 hours and picked them up with tongues and placed on a paper towel, then they were measured. ...read more.


If enough water enters the cell by osmosis, the cell can swell enough to burst open and die. This is demonstrated in the picture below. In this picture a red blood cell is put in a glass of distilled water (all water with no salt or sugar in it). Because there is a higher concentration of water outside the cell, water enters the cell by OSMOSIS. In this case too much water enters and the cell swells to the point of bursting open. In the end pieces of cell membrane are left in the water. Pieces of red blood cell membranes are known as red blood cell ghosts. Evaluation I think in this experiment worked well in certain aspects, because our results show a reliable trend, which agrees with my prediction. I have also been able to analyze the evidence. I found that the necessary concentration at which there will be no change to the chip would be between 0M and 2M. In this experiment everything happened as I expected I have gained knowledge of what osmosis is and may go into more detail in the future. The methods used in this experiment worked because they were fair, a fair test is needed to get right results our results were written down after then experiment to show what had happened over night. ...read more.

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