In the experiment performed various reagents were added to both Elodea leaves and purple onion skin to observe plasmolysis and deplasmolysis of the cell membrane. During plasmolysis the cell membrane shrinks away from the cell wall (noted especially in purple onion skin) and the chloroplast become aggregated in the middle of the cell (noted especially in Elodea). This is happening because the water inside the cell is being drawn out via osmotic pressure. In deplasmolysis the opposite effects occur and the cell returns to normal (although not to quite the same extent depending on the length of time of plasmolysis). Using the NaCl solutions, the time till plasmolysis of the cell rapidly increased and was more severe for the higher concentration. Using the graded sucrose solutions plasmolysis occurred most severely with the 2M concentration with a lasting effect even after trying to deplasmolyze the cells. Using the 0.5M concentration only slight plasmolysis was noted in Elodea while no visible plasmolysis was noted in the purple onion skin. Also noted in Elodea was the movement of the interstitial fluid in a counterclockwise direction around the cell. The reason for these observations may be that the 0.5M concentration may be isotonic for the purple onion skin and near isotonic for Elodea in which case there would essentially be no net movement of water into or out of the cell. In using the various alcohols observations were made with ethanol over a time period of approximately 10 minutes. Initially there was no visible change for the purple onion skin while the Elodea showed a slight plasmolysis. Over the time period purple onion skin showed no observable signs of plasmolysis while Elodea progressively underwent increased plasmolysis. The reasons for these different observations may lie in the partition coefficient of the reagent as compared to the relative amount of cell wall tissue in both the purple onion skin and Elodea. Since the reagent was able to penetrate the Elodea and exact an effect, the purple onion skin may in fact have a thicker cell wall or possibly other macromolecular factors embedded in its tissue that make it more difficult to penetrate for the reagent. Performing this same experiment with a reagent with a higher partition coefficient and comparing the results to the current ones will help assess the validity of this hypothesis. From class data ethanol showed the fastest and most severe rate of plasmolysis while glycerol showed hardly any effect at all over extended period of time. The remaining alcohol reagents showed various extents of plasmolysis over varying amounts of time within the observations made by the two aforementioned reagents