tonicity on cell membrane lab report
Effects of Tonicity on Cell Membrane
Abstract The purpose of this experiment was to determine the effects of tonicity on a cell membrane using red blood cells, potato strips and three unknown solutions (A, B, C). First three slides were prepared containing RBC’s and unknown solutions A, B and C. A control slide was prepared only using RBC’s. After observing each slide under the microscope it was determined that unknown solution A was hypertonic because the RBC appeared to have shrunk. The RBC in unknown solution B appeared to be swollen, therefor, the tonicity of unknown solution B was hypotonic. Unknown solution C showed no change to the RBC shape, it was suggested that unknown solution C was isotonic. To confirm the tonicity of unknown solutions A, B and C, a potato strip was placed in 3 separate tubes containing each unknown solution. After each potato strip soaked for twenty minutes it was proven; unknown solution A was hypertonic due to the flaccidity of the potato strip. Unknown solution B proved to be hypotonic because the potato felt extremely rigid. Lastly, the potato strip soaking in unknown solution C was flexible which proved to be isotonic. From those results each unknown solution was established and allowing the determination of tonicity for unknown solutions A, B and C.
Introduction
The cell membrane was discovered by Swiss botanist Carl Naegeli and C. Cramer in 1855.2 The cell membrane, also known as the plasma membrane is a phospholipid bilayer. Each phospholipid molecule contains a polar head, composed of a phosphate group and glycerol that is hydrophilic (water-loving) and soluble in water, as well as a nonpolar tail, composed of fatty acids that is hydrophobic (water-fearing) and insoluble in water.3 The polar heads are on the two surfaces of the lipid bilayer facing the extracellular and intracellular environment, while the nonpolar tails are in the interior of the bilayer away from the water. Because the fatty acid
Abstract The purpose of this experiment was to determine the effects of tonicity on a cell membrane using red blood cells, potato strips and three unknown solutions (A, B, C). First three slides were prepared containing RBC’s and unknown solutions A, B and C. A control slide was prepared only using RBC’s. After observing each slide under the microscope it was determined that unknown solution A was hypertonic because the RBC appeared to have shrunk. The RBC in unknown solution B appeared to be swollen, therefor, the tonicity of unknown solution B was hypotonic. Unknown solution C showed no change to the RBC shape, it was suggested that unknown solution C was isotonic. To confirm the tonicity of unknown solutions A, B and C, a potato strip was placed in 3 separate tubes containing each unknown solution. After each potato strip soaked for twenty minutes it was proven; unknown solution A was hypertonic due to the flaccidity of the potato strip. Unknown solution B proved to be hypotonic because the potato felt extremely rigid. Lastly, the potato strip soaking in unknown solution C was flexible which proved to be isotonic. From those results each unknown solution was established and allowing the determination of tonicity for unknown solutions A, B and C.
Introduction
The cell membrane was discovered by Swiss botanist Carl Naegeli and C. Cramer in 1855.2 The cell membrane, also known as the plasma membrane is a phospholipid bilayer. Each phospholipid molecule contains a polar head, composed of a phosphate group and glycerol that is hydrophilic (water-loving) and soluble in water, as well as a nonpolar tail, composed of fatty acids that is hydrophobic (water-fearing) and insoluble in water.3 The polar heads are on the two surfaces of the lipid bilayer facing the extracellular and intracellular environment, while the nonpolar tails are in the interior of the bilayer away from the water. Because the fatty acid
References: 1. Chamberlain et al. Effects of Tonicity on Cell Membrane . Human Physiology Labratory Manual, 8th Edition, Expt 6 part C and D 2. Chronology of Life. http://www.whatislife.com/education/fact/history_table.html. Accessed November 22nd, 2014. 3. Tortora GJ. Functional Anatomy of Prokaryotic and Eukaryotic Cells. In: Microbiology an Introduction. 9th ed. San Francisco, CA: Pearson Education, Inc; 2007: 77-113. 4. Osmosis Background. http://rheneas.eng.buffalo.edu/wiki/Osmosis:Background. Accessed November 22nd, 2014. 5. Fox SI. Interactions Between Cells and the Extracellular Environment. In: Human Physiology. 12th ed. New York, NY: McGraw-Hill;2011:129-159. 6. Campbell, N., & McClendon, J. (2014, October 24). Cytolysis. Retrieved November 23, 2014, from http://en.wikipedia.org/wiki/cytolysis