Activity 1. Plasma Membranes
1. What substances can and cannot pass through the lipid bilayer?
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The substances that can pass through the lipid bilayer are the small uncharged molecule. On the other hand, this layer is impermeable to larger polar molecules such as glucose, amino acids, and ions.
2. What factors contribute to a concentration and electrical gradient?
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A factor that contributes to the concentration gradient is when the concentration of particles is higher in one area than in another. While the factor contributing to the electrical rise is the difference in ion concentrations on either side of the membrane, the ion charge (for example, Na+, Ca++, Cl-), and the voltage difference between the two sides of the membrane (the transmembrane potential).