Cell membrane

993 Words4 Pages
In life, it is critical to understand what substances can permeate the cell membrane. This is important because the substances that are able to permeate the cell membrane can be necessary for the cell to function. Likewise, it is important to have a semi-permeable membrane in the cell due to the fact that it can help guard against harmful items that want to enter the cell. In addition, it is critical to understand how water moves through the cell through osmosis because if solute concentration is unregulated, net osmosis can occur outside or inside the cell, causing issues such as plasmolysis and cytolysis. The plasma membrane of a cell can be modeled various ways, but dialysis tubing is especially helpful to model what substances will diffuse or be transported out of a cell membrane. The experiment seeks to expose what substances would be permeable to the cell membrane through the use of dialysis tubing, starch, glucose, salt, and various solute indicators. However, before analyzing which of the solutes (starch, glucose, and salt) is likely to pass through the membrane, it is critical to understand how the dialysis tubing compares to the cell membrane. Dialysis tubing is made from regenerated cellulose or cellophane, and is used in clinical circumstances to ensure that molecule have a filtered flow, and that larger solute molecules do not enter the dialysis tubing. Like a cell membrane, dialysis tubing has a semi-permeable membrane, which allows small molecule to permeate through the membrane. Thus, the dialysis tubing mimics the diffusion and osmosis processes of the cell membrane. Although the dialysis tubing has a semi-permeable membrane, which mimics a cell, its structure is different. The membrane that surrounds the cell i... ... middle of paper ... ...ld move freely inside and outside of the cell, however, because there is a greater solute concentration inside the cell, the water would diffuse through osmosis into the cell model, increasing the final mass of the dialysis tubing and causing cytolysis. Works Cited Alberts B, Johnson A, Lewis J, et al., New York: Garland Science; 2002. Buckley, James M. "[Regents Prep Living Environment] Laboratory: Indicators." [Regents Prep Living Environment] Laboratory: Indicators. N.p., 2003. Web. 12 Nov. 2013. DR. Jakubowski. "TRANSPORT AND KINETICS." BC Online: 6A: Passive and Facilitated Diffusion. N.p., 12 Mar. 2013. Web. 05 Nov. 2013. Reece, Jane B. Campbell Biology: Concepts & Connections. San Francisco, CA.: Benjamin Cummings, 2012. Print. Sense, Fred. "How Does Starch Indicate Iodine?" General Chemistry Online: FAQ: Redox Reactions:. N.p., 2010. Web. 12 Nov. 2013.
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