Diffusion

All molecules have the tendency of moving from an area of high concentration to an area of low concentration. This is called diffusion. Diffusion results because of the random movement of particles. The diffusion of water into and out of a selectively permeable membrane is called osmosis. The cell membrane is similar to the selectively permeable membrane, which can be diffused only by water and other very small particles through osmosis. When the external and internal solute concentration are equal, there is no movement of water will be observed. Cells will maintain normal. This is described as isotonic. Osmosis does not occur in an isotonic solution. A hypotonic solution is a solution in which the concentration of dissolved substances is lower than the concentration inside the cell. If a cell was put in a hypotonic solution, osmosis will cause water to move through the cell membrane into the cell. A solution is hypertonic if its concentration of dissolved substances is greater than the concentration inside the cell. If a cell placed in a hypertonic solution, it would lose water.

The purpose of this experiment was to make observations and conclusions about the ability of cells to adjust to varying chemical concentrations in the environment and to observe the effect of isotonic, hypotonic and hypertonic solution on cells. I hypothesize that when the sucrose concentration will change, the mass will also change.

For this experiment, the following materials were used: potatoes, a balance, distilled water, sucrose solution and seven beakers. Each of the beakers were labeled with a different sucrose concentration (0.0; 0.1; 0.2; 0.3; 0.4; 0.5; 0.6). The potato cores are weighted to the nearest 0.01 g on the aluminum sheet on the balance, and record in the initial weight columns of the data table, and then put them into the beakers. After that, the sucrose solutions are placed in the beakers according to their labels. The solutions will be in the beaker for about one and half hours. After one