Ap Biology Dialysis Experiment

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Our goal of the dialysis experiment was firstly, to answer the question of why the dialysis cells appeared smaller after adding sugar water and secondly, to prove our hypothesis that water molecules move out of the cell because the concentration of water is greater than inside the cell than it is outside the cell. This experiment was conducted with one control group and one experimental group. The independent variable was the concentration of water, (water and glucose solution). The dependent variable was the size of dialysis cells afterward the lab, measured by the mass and the amount of water. The dialysis cell represents the plant cells in real life. The two pieces of dialysis cells (Cell A and Cell B), was filled in with 10mL of water. …show more content…
Cell A was 9.6 grams and Cell B was 9.63 grams before the experiment. Then, dialysis Cell A was placed in a cup with 70 mL of water, and dialysis Cell B was placed in a cup with 70 mL of 5% glucose and 95% water solution. The two dialysis cells were left in the water for three days. After three days, we removed dialysis Cell A and dialysis Cell B from each cup. After wiping the remnants of water on the outside of the dialysis cells, we placed each cell for the mass of the cell. Dialysis Cell A was 9.66 grams, while dialysis Cell B was 6.2 grams. The amount of liquid in each of the dialysis cells (Cell A & Cell B) was different. Dialysis Cell A had 8.6 mL of liquid inside the cell, and dialysis Cell B had 7.6 mL of liquid inside the cell. The mass of dialysis Cell A had increased 0.06 grams over the three days, and the mass of dialysis Cell B had decreased 3.45 grams over the three days. The amount of liquid in the cell in dialysis Cell A had decreased 1.4mL over the the three days, and the amount …show more content…
When we first started off the experiment, dialysis Cell A was placed in 100% water, which had an equal concentration outside and inside the cell. However, dialysis Cell B was placed in 5% glucose and 95% water solution, therefore making the concentration of water inside the cell (100% water), greater than the concentration of water outside the cell (95% water). This data has proved the concept of osmosis in the cells, related to our claim that water molecules move out of the cell because the concentration of water is greater inside therefore cell than it is outside the cell. The cells have to maintain a balance so that the concentration of water inside and outside the cell is equal. This is why the water molecules in Cell B had mostly moved out of the dialysis tubing to keep the concentration of water equal both outside and inside the cell. We also conducted the Benedict test for Cell A and Cell B. We saw that Cell A had no glucose, but Cell B had glucose. From this, we could see that both water and glucose moved through the selectively permeable membrane of the dialysis Cell B. The glucose moved inside the cell so that it could also balance out the concentration of water outside and inside the cell. This also proved the concept of osmosis as well, where the water moved outside of the cell because of the

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