Observing Diffusion And Osmosis On The Rate Of Diffusion Across A Cell Membrane

1384 Words Oct 19th, 2014 6 Pages
Observing Diffusion and Osmosis
Purpose and Hypothesis:
Procedure 1(Surface Area and Cell Size)-
*Purpose-How do surface area and cell size affect the rate of diffusion across a cell membrane?
*Hypothesis-The cell with the greatest surface area to volume ratio will have the most affective rate of diffusion.
Procedure 2(Modeling Diffusion and Osmosis)-
*Purpose-How does the molarity of the solution affect the diffusion and osmosis across a semi-permeable membrane?
*Hypothesis-The solution will move from an area of low water potential to an area of high water potential and the higher the molarity, the more water will move into the membrane.
Procedure 3(Observing Osmosis in Living Cells)-
*Purpose-How do different solutions and water potentials affect the movement of water across a cell membrane?
*Hypothesis-The water will move from an area of high water potential to an area of low water potential.
Background Information:
To maintain homeostasis, cells must move materials in and out of their cell membranes. The cell membranes are semi-permeable, which helps to regulate what enters and leaves the cell. Phospholipid fatty acids are hydrophobic, meaning they dislike water and help to limit the movement of water across the membrane. The membrane is actually a phospholipid bilayer containing embedded proteins. In the cell’s environment the solvent that the solutes dissolve in is water; this environment is called aqueous. Water can pass through the membrane by osmosis, however, a…
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