Soraya Pashaei-MarandiBIO 111-Section 521Assignment #2-Properties of WaterThe purpose of the plasmolysis experiment was to determine the effect of solute concentrations on water movement within Elodea plant cells and animal blood cells. The hypothesis is that with an increase in saline concentration, the cells will go from hypotonic to isotonic to hypertonic. The null hypothesis is that the differences in saline concentrations will have no adverse affects on the cells. During osmosis, water always moves from an area of greater water potential to an area with lower water potential. The water potential can be affected by the amount of pressure and the presence of solutes. The dissolved solutes cause water to move from an area of low solute concentration to an area of higher solute concentration. The direction of the water movement can be halted with osmotic pressure. Osmotic potential is the inverse of osmotic pressure and determines whether the solutions are isotonic, hypertonic, or hypotonic. During the Elodea plant experiment, three slides were observed to determine whether the solutions were hypotonic, isotonic, or hypertonic. The first slide had Elodea mounted in distilled water. After viewing it under the microscope, it was determined the solution was hypotonic. The cells swelled due to inward osmotic pressure causing the central vacuole to expand; however, the cell did not burst due to the cell wall. The Elodea mounted in .9% saline solution represented an isotonic solution where the cell remained in dynamic equilibrium. The Elodea in 5% saline solution was a hypertonic solution where the chloroplasts were all clumped into the middle of the cell. As for mammalian red blood cells, .9% saline solution is an isotonic state. Hemolysis occurs when cells burst due to water entering the red blood cells in hypotonic solutions. Crenation is when red blood cells lose water and shrivel in a hypertonic solution. For the animal blood experiment, tube number one contained 1.8% saline with no distilled water. The blood became a darker red and was unreadable due to it being a hypertonic solution. The second tube contained .9% saline with distilled water which was an isotonic solution, but wasstill unreadable. The third tube had no saline solution but did have distilled water. Due to the solution being hypotonic, the blood was easy to see
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