In our Egg Diffusion Lab, we put two eggs in vinegar to dissolve the egg shell. Then we recorded the mass and circumference and put one egg in deionized water and the other in sugar water. The egg in DI water grew and the egg in sugar water shrank.
When the sugar concentration increased, the egg mass and circumference decreased. This was because it was in a hypertonic solution, meaning there was more solute (sugar) outside of the cell (egg) then inside the egg. When a cell is in a hypertonic solution, the egg shrinks because the solvent (water) inside the cell passes through the cell membrane and leaves the cell. Since there is a higher concentration of solvent inside the cell compared to the low concentration of solvent outside the cell, the water will leave the cell because diffusion says that molecules always go from an area of high concentration to an area of low concentration. The mass and circumference of the eggs decreased because water left the cell.
A cell's internal environment changes as its external environment changes because a cell always wants to be in equilibrium. When there is a higher concentration of solute outside the cell, the cell will want to balance it out by releasing solvent and decreasing their own size. When we put the egg in vinegar, in addition to dissolving the egg shell, the egg also increased in size because there was a higher concentration of solvent outside the egg than there was inside. Solvent moved into the egg when we soaked it in vinegar. When we put the egg in water, the size increased even more. More solvent went inside the cell. A lot of our eggs burst because there was so much solvent inside the cell. When we put the egg in sugar water, the egg shrank because the water inside the cell moved to outside the cell. Since the sugar water had a very high concentration of solute, the solvent from inside the cell wanted to go across the cell membrane and leave the cell.
This lab demonstrates passive diffusion because it showed us that the egg grows or shrinks depending on what its external conditions are like. The cell didn't use any energy to diffuse, so it is called passive diffusion. In class, we learned about passive diffusion and that it doesn't require any energy to diffuse. It demonstrated passive diffusion because the cell grew and shrank without using any energy. The solvent moved across the cell membrane whether or not it was in water or sugar water.
Fresh vegetables are sprinkled with water in supermarkets because the vegetables need to stay crisp and fresh for consumers to purchase it. The water diffuses into the vegetables and allows the turgor pressure inside the cells to keep the vegetable fresh and not shriveled up. When the cell swells because water diffuses into it, the turgor pressure inside the cell increases. When salt is used to melt ice on roads, the plants on the side of the roads will shrivel up and possibly die. Salt will take away the water inside the plant cells because of the high concentration of solute (salt) outside the cells. When the water from the cells leaves, the turgor pressure in the cells decreases and makes the cells shrink. When plant cells don't have turgor pressure, the plant becomes limp.
Based on this experiment, I would want to test what happens when you water a plant with salt water then water then salt water etc. Just out of curiosity, I would want to know how long it would take for the plant to shrivel up when it is watered with salt water and then how long it takes for the plant to perk back up after it's watered with DI water for a while. In 5th grade we did an experiment with an egg and karo syrup and water and we kept switching out the karo syrup for water and vice versa for weeks and weeks. So seeing that done but with a plant would be interesting to experiment with because it isn't just one cell, it's a whole bunch of cells. Experimenting with a plant would also be different than experimenting with an egg because it isn't an animal cell either.
| Group | 2 | 3 | 4 | 5 | 6 | 7 | 8 | Average | |
| DI Water | % change (mass) | N/A | -0.74 | 0.37 | 0.45 | N/A | 6.95 | N/A | 1.8 |
| % change (circumference) | N/A | 1.2 | 1.7 | 0 | N/A | 14.37 | N/A | 4.3 | |
| Sugar Water | % change (mass) | -52.8 | -52.8 | -49.7 | -41.71 | -39.58 | -14.7 | -46.7 | -47.25 |
| % change (circumference) | -18.3 | -26.3 | -26.6 | -32.35 | -21.21 | -13 | -22.4 | -22.94% |
A cell's internal environment changes as its external environment changes because a cell always wants to be in equilibrium. When there is a higher concentration of solute outside the cell, the cell will want to balance it out by releasing solvent and decreasing their own size. When we put the egg in vinegar, in addition to dissolving the egg shell, the egg also increased in size because there was a higher concentration of solvent outside the egg than there was inside. Solvent moved into the egg when we soaked it in vinegar. When we put the egg in water, the size increased even more. More solvent went inside the cell. A lot of our eggs burst because there was so much solvent inside the cell. When we put the egg in sugar water, the egg shrank because the water inside the cell moved to outside the cell. Since the sugar water had a very high concentration of solute, the solvent from inside the cell wanted to go across the cell membrane and leave the cell.
This lab demonstrates passive diffusion because it showed us that the egg grows or shrinks depending on what its external conditions are like. The cell didn't use any energy to diffuse, so it is called passive diffusion. In class, we learned about passive diffusion and that it doesn't require any energy to diffuse. It demonstrated passive diffusion because the cell grew and shrank without using any energy. The solvent moved across the cell membrane whether or not it was in water or sugar water.
Fresh vegetables are sprinkled with water in supermarkets because the vegetables need to stay crisp and fresh for consumers to purchase it. The water diffuses into the vegetables and allows the turgor pressure inside the cells to keep the vegetable fresh and not shriveled up. When the cell swells because water diffuses into it, the turgor pressure inside the cell increases. When salt is used to melt ice on roads, the plants on the side of the roads will shrivel up and possibly die. Salt will take away the water inside the plant cells because of the high concentration of solute (salt) outside the cells. When the water from the cells leaves, the turgor pressure in the cells decreases and makes the cells shrink. When plant cells don't have turgor pressure, the plant becomes limp.
Based on this experiment, I would want to test what happens when you water a plant with salt water then water then salt water etc. Just out of curiosity, I would want to know how long it would take for the plant to shrivel up when it is watered with salt water and then how long it takes for the plant to perk back up after it's watered with DI water for a while. In 5th grade we did an experiment with an egg and karo syrup and water and we kept switching out the karo syrup for water and vice versa for weeks and weeks. So seeing that done but with a plant would be interesting to experiment with because it isn't just one cell, it's a whole bunch of cells. Experimenting with a plant would also be different than experimenting with an egg because it isn't an animal cell either.
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