The plasma membrane is a good barrier because it has:
A) cholesterol embedded within the bilayer to add rigidity to its structure
B) proteins that adhere to cytoskeleton fibers to help anchor the cell in place.
C) fatty acid tails within the lipid bilayer that create a
hydrophobic region making it difficult for polar molecules to pass through
D) proteins embedded within the bilayer to keep substances out
E) polar head groups at the surface of the lipid bilayer that
create a hydrophilic region making it difficult for charged
molecules to pass through
The phospholipid bilayer formed by these interactions makes a good barrier between the interior and exterior of the cell, because water and other polar or charged substances cannot easily cross the hydrophobic core of the membrane.
