Introduction
Tonicity refers to the concentration of solutes in a solution (Lab 6-7). There are three stages of tonicity: Isotonic, hypertonic and hypotonic. Four unknown solutions were given and labeled as followed: Solution A, Solution B, Solution C, and Solution D. Since potato cells were used for this type of experiment, in an Isotonic solution the solute and water concentration are the same as inside the cell in which the isotonic solution contains 0.9% NaCl. In other words, water moves in and out in the same amount without causing any changes. In a hypertonic environment, the solute concentration is greater and water concentration is less outside the potato cell in which the hypertonic solution contains 10.0% NaCl. This solution will cause the potato cells to loose water and shrink and if too much water is loss the cell may die as well. In a hypotonic environment, the solute concentration is lower and there is a higher water concentration outside of the cell. The flow of the water occurs inwards into cells provoking the cells to burst. The term used to describe the bursting of the cells is called (lyse) and then the cells die. The hypotonic solute contains 0.2% NaCl.
Hypothesis
My first hypothesis for this tonicity experiment was if a piece of potato is immersed or put into the hypertonic solution A, then the solute concentration will be greater and water concentration will be less outside of the cell, which will cause the piece of potato to decrease in size. Moreover, my second hypothesis was if a piece of potato is immersed or put into the hypotonic solution B, then the piece of potato will swell or increase in size by the solute moving inwards inside of the cell. My third and final hypothesis was if a piece of potato is immersed or put into the isotonic solution C, then the piece of potato will remain the same in size by not having any major changes by the solution.
Materials and Methods This experiment was followed as
Cited: Hoefnagels, Mariëlle. "The Energy of Life." Biology: Concepts and Investigations. New York: McGraw-Hill, 2012. 80-81. Print. Erdahl, Emma G., Betty L. King, David L. Parker, George G. West, and Mary F. Wise. "Lab 6- 7." General Biology Study Guide and Laboratory Manual. Tenth ed. New York: NVCC-Alexandria, 2007. N. pag. Print. Table No. 1 Tonicity Solutions Results Graph No. 1 Graph No. 2