Osmosis and Diffusion Lab Report Introduction All Cells Contain Membranes That Are Selectively Permeable, Allowing Certain Things to Pass Into and Leave Out of the Cell. the Process in Which Molecules of a Substance

1011 Words Oct 12th, 2012 5 Pages
Introduction
All cells contain membranes that are selectively permeable, allowing certain things to pass into and leave out of the cell. The process in which molecules of a substance move from an area of high concentration to areas of low concentration is called Diffusion. Whereas Osmosis is the process in which water crosses membranes from regions of high water concentration to areas with low water concentration. While molecules in diffusion move down a concentration gradient, molecules during osmosis both move down a concentration gradient as well as across it. Both diffusion, and osmosis are types of passive transport, which do not require help.
When the concentration of the environment outside of the cell is lower than the inside
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Results
The potato cores started to decrease in weight as the molarity went up. The potatoes that gained weight were the potatoes placed in deionized water, and the sucrose solution molarity of 0.1.
However, the potatoes started losing weight in the sucrose solution of 0.2 and up.
Sucrose Molarity 0 M 0.1 M 0.2 M 0.3 M 0.4 M 0.5 M 0.6 M
Final Weight (g) 5.1g 5g 4.7g 4.5g 4.2g 4.1g 4.2g
Initial Weight (g) 4.4g 4.5g 4.4g 4.3g 4.4g 4.5g 4.4g
Weight Change (g) 0.7g 0.5g -0.3g -0.2g -0.2g -0.4g -0.2g
% Change in Weight 15.9g 11.1g -6.82g -4.65g -4.55g -8.89g -4.55g

Table 1:

Discussion
When the potato gains weight it was in a hypertonic solution, and when the potato loss weight it was in a hypotonic solution. If the potato would not have changed weight it would have been an isotonic solution, but that was not the case in this experiment. The potato either gained, or lost weight. This data therefore supports the hypothesis that the potato that would be more hypertonic to the sucrose solution and would gain weight, whereas the potato would be hypotonic to the solution and would lose weight. Based on the data from the graph, the osmolarity of the potato was 0.4 M. Osmolarity is the molar concentration of when there is no change in the weight of the potato. In

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