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Discovering the Lowest Concentration Of Lead Ions Needed to Cause the Loss of Partial Permeability of Red Onion Cell Membranes
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| Submitted: Sun Dec 15 2002
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Discovering the Lowest Concentration Of Lead Ions Needed to Cause the Loss of Partial Permeability of Red Onion Cell Membranes Aim: To discover the lowest concentration of lead ions needed to cause the loss of partial permeability of red onion cell membranes. Prediction: I predict the lowest concentration of lead ions to cause the loss of partial permeability in red onion cell membranes to be 0.4M Background Knowledge Lead ions reduce the partial permeability of cell membranes. The principle mechanism by which lead does this is by reduction in pore size and by reducing the solubility of the phospholipid bilayer, the principle material from which cell membranes made. Pores are proteins which allow uninhibited access to water molecules to and from the cell. These proteins contain thiol groups (-SH), to which lead ions have a particular affinity. A reduction in solubility reduces the permeability of the cell membrane to water; a less polar phosphate...
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