Simple Diffusion Lab

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Cells use various methods of transportation to move material in and out of the cell. The semi-permeable plasma membrane surrounds the cell and allows certain materials to enter and exit the cell. Simple diffusion is movement of molecule through the plasma membrane without the help of any channel or proteins. In simple diffusion molecule move down their concentration gradient; as a result, they don’t require energy input. In the computer simulated lab for simple diffusion, nothing will move across the membrane because NaCl, urea, albumin and glucose are all too big to go through the semi-permeable membrane. Facilitated diffusion is movement of particles from high concentration to low concentration with the help of a carrier protein channel. …show more content…
My results reject the hypothesis that nothing will move across the semipermeable membrane because NaCl, urea and glucose were able to diffuse across the membrane. Albumin was the only solute that didn’t diffuse at all throughout the simple diffusion process. NaCl began diffusing through the membrane after the molecular weight cutoff (MWCO) was increased to 50. Previously, the membrane holes were too small for any particle to go through. After the MWCO size increased, NaCl was able to diffuse across the membrane with an average diffusion rate of 0.0150 …show more content…
Osmotic pressure builds up when there is a difference in concentration of solute on either sides of the experiment. I hypothesized that all of the solutes will display osmotic pressure however only the initial NaCl with 20 MWCO, albumin with all the different MWCO, and glucose with 20, 50, 100 MWCO displayed osmotic pressure. These were all the solutes that didn’t diffuse; as a result, osmotic pressure build up in the experiment. The initial 8 mM NaCl with 20 MWCO displayed the most pressure at 272 mm Hg because, just like in simple diffusion with 20 MWCO of NaCl, the 8mM of NaCl didn’t diffuse across the membrane until the membrane size increased to 50 MWCO, causing a significant amount of pressure to build up. Once the membrane level increased to 50 MWCO, the pressure level disappeared because the solute were able to diffuse across the membrane. This also causes NaCl to appear in the right beaker at 50

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