Cells have membranes that allow them to establish and maintain internal environments that are different from their external environments. The structure of the phospholipid bilayer influences its permeability.

Which statements accurately reflect the permeability of the cell membrane? Choose all that apply.

The hydrophilic part of the cell membrane is A, the phosphate head.
The lipid tails are hydrophobic and will only allow molecules which are small and polar to pass through.
Molecules that are large or charged must use a channel protein, such as D, to cross the cell membrane.
Molecules using membrane proteins, such as E, for transport require energy.
Charged molecules, such as K+ or Ca++ are unable to pass through the lipid bilayer because of their charge and must use a membrane protein to cross the cell membrane.
C, the lipid tails, are hydrophobic and repel water.