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How much sugar that a vegetable will acquire during the process of osmosis.

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Introduction

Biology Coursework 1. Intro 2. Hypothesis 3. .Method 4. Appartatus 5. Variables 6. Results 7. Conclusion 8. Evaluation Introduction We must prepare an investigation to find out how much sugar that a vegetable will acquire during the process of osmosis. For this study I will be placing 4 vegetables of precise measurements into 6 different solutions ranging from 0.0 to 1.0 molars of sugar. I will now explain osmosis briefly. Some membranes in plant and animal cells allow certain particles to pass through them and not others. They are selectively permeable. * The diffusion of water through a selectively permeable membrane is called osmosis. The rate at which osmosis takes place is affected by the concentration of water in the two solutions on each side of the membrane. * If a selectively permeable membrane separates the two solutions, water moves through it in both directions at the same time. However, more water leaves a dilute solution (high water concentration) and passes into a more concentrated solution (low water concentration) than enters it. Although the water appears to move across the membrane in one direction, it is in fact moving in both directions but more one way than the other. * When the concentration of water is the same on both sides of the membrane, the movement of water will be the same in both directions. At this point, the net exchange of water is zero and the system is in equilibrium. ...read more.

Middle

This meant that the carrot gave out a lot of water after the sugar concentration became higher than 0.42 molar. The turnip had a sugar concentration of 0.63 molar. This meant that in the low sugar concentrations, the turnip took in a lot of water because it had a low concentration of water. As the sugar concentration began to increase, the turnip gradually took in less water, then at 0.63 the turnip stopped taking in water and began to give out water because it had a higher concentration of water then the sugar solution in the test tube. The potato had a sugar concentration of 0.21 molar. This meant that in the lower sugar concentrations the potato took in small amounts of water. Then as the concentration of sugar increased slightly, the potato gave out high amounts of water. This is because the potato had a low concentration of sugar. The parsnip had a sugar concentration of 0.19 molar. This meant that in the lower concentrations of sugar, the parsnip took in small amounts of water but as the concentration increased slightly the parsnip gave out large amounts of water. This is because the parsnip had a very small concentration of sugar. Osmosis caused the increase and decrease in the length of the vegetables. The vegetables took in water when their inner sugar concentration was higher than in the test tubes because there was a higher concentration of water in the test tube than in the vegetable. ...read more.

Conclusion

The cylinders may also have given out or taken in salts during osmosis. This is because the salt concentration was unequal between the sugar solution and the cylinder of vegetable. If the cylinder did take in or give out salts then the cylinder may have been slightly smaller or larger than it should have been. This would mean that my results would have been slightly different than they should have been. The vegetables used may also have been slightly rotten. This would mean that the cell membrane would have begun to break down and would not allow molecules to flow in or out of the vegetable very easily. This would mean that the vegetable would not perform osmosis and so would not increase or decrease in size. My results for the carrot show that in 0.4 and 0.6 molar of sugar the vegetable did not change in size. This could have been caused because the carrot was slightly rotten and would not perform osmosis. Apart from these small problems, the experiment was performed quite well and the results were fairly accurate. But if we really wanted to be confident about the results then I would have to repeat the experiment and take in to account all of these small problems. If I were to extend the extend the experiment then I would use more sugar concentrations, such as 0.1,0.3 molar of sugar. This would provide us with a larger set of results and allow for any anomalous results. I would also increase the range of vegetables used because it would give us more results to compare. ...read more.

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