In life, it is essential to understand what substances can penetrate the cell membrane. This is important because substances capable of penetrating the cell membrane may be necessary for the cell to function. Likewise, it is important to have a semi-permeable membrane in the cell because it can help protect against harmful elements that wish to enter the cell. Additionally, it is essential to understand how water moves through the cell by osmosis, because if the solute concentration is not regulated, net osmosis can occur outside or inside the cell. cell, causing problems such as plasmolysis and cytolysis. The plasma membrane of a cell can be modeled in many different ways, but dialysis tubes are particularly useful for modeling substances that will diffuse or be transported out of a cell membrane. The experiment aims to discover which 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) are likely to pass through the membrane, it is essential to understand how the dialysis tube compares to the cell membrane. Dialysis tubing is made from regenerated cellulose or cellophane, and is used in clinical circumstances to ensure that molecules have a filtered flow and that larger solute molecules do not enter the dialysis tubing. Like a cell membrane, the dialysis tube has a semi-permeable membrane, which allows small molecules to penetrate through the membrane. Thus, the dialysis tube mimics the diffusion and osmosis processes of the cell membrane. Although the dialysis tube has a semi-permeable membrane that mimics a cell, its structure is different. The membrane that surrounds the cell in the middle of the paper would move freely in and out of the cell, however, as there is a greater concentration of solute inside the cell, the water will would diffuse through osmosis into the cell model, increasing the final mass of the dialysis tube 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. NP, 2003. Web. November 12, 2013.DR. Jakubowski. “TRANSPORT AND KINETICS.” BC Online: 6A: Passive and facilitated distribution. Np, March 12, 2013. Web. November 05, 2013.Reece, Jane B. Campbell Biology: concepts and connections. San Francisco, CA: Benjamin Cummings, 2012. Print.Sense, Fred. “How does starch indicate iodine? General chemistry online: FAQ: Redox reactions:. NP, 2010. Web. November 12. 2013.