Wednesday, September 4, 2019

An Investigation into the Factors which Affect Osmosis Essay -- GCSE B

An Investigation into the Factors which Affect Osmosis Osmosis is defined as the movement of water molecules from a higher concentration to a lower concentration through a partially permable membrane. Osmosis occurs with molecule moving in and out, these molecules move across the plant’s cell membrane. The plant’s cell membrane is partially permable and therefore it has small holes in it which allow for small water molecules to pass through it however larger molecules such as glucose through. However on the out side of the plant cells there is a cell wall of cellulose that has larger holes that let anything pass through it. This cell wall is totally permeable and therefore will allow larger molecules such as glucose through it, but the larger molecules can still not pass the cell membrane. When these cells are in a solution which has a higher concentration of water than the cells concentration of water the water will diffuse into the cell as the water moves from a higher concentration (the solution) to the lower concentration (the cells.) As more and more water enters the cell the cell wall starts to expand and the cell starts to become turgid. Even is a plant cell is placed in a solution where there is a high water concentration and a weak sugar solution (say a 0.1 d/mol3 strong) there will still be more water outside the cell than inside the cell therefore there will still be an increase in volume and weight. This means that when the plant cells are placed in a strong sugar solution (where there is more sugar than water.) there will be a decrease in weight and volume. This process is defined as plasmolysis. This is where the cell membrane pulls away from the cell wall, this is because a lot of water has been moved from the cell as the plant cell has the strong concentration of water and the solution has a weak concentration the water will move from the plant top the water. Sometimes the cell will shrivel up completely and it becomes flaccid. This is represented in the diagram below With osmosis occurring there will eventually be a point where the concentration of water will be equal to the concentration inside the cell. This means that with the water still diffusing in and out there will be equal amounts going in and out. This means that osmosis is still occurring but the plant or the solution is either gaining o... ...ainst the cell wall, the tugor pressure will reach it’s maximum and the cells will not be able to take in any more water. At the other end of the line, I would expect the line to eventually curve off horizontally. Once the cell becomes flaccid and the cell membrane collapses, no more water would be able to escape. I did predict that the stronger the solution the more the potato chips would lose weight. I believe my results have proven this. Evaluation I am pleased with the way my experiment has gone, I did not come across too many problems and most of my points on the graph were close to the line of best fit. Therefore I am happy with the accuracy of my results. I think my method was adequate for producing accurate results I could still improve it. I could’ve also tried to measure the potato chips more accurately when cutting them. I feel my investigation on the whole was a sucsess. I achieved reliable and accurate results. however I could increase my confidence in my conclusions by repeating the experiment with another carrot to back it up. But on the whole my experiment matched my prediction and I am happy about my results and the way I conducted it.

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