Which of the following CANNOT diffuse through the plasma membrane?

A) lipid-soluble molecules
B) water-soluble ions
C) proteins
D) water

Plasma Membrane

The lipid bilayer membrane surrounding cytoplasm of a cell, regulating the passage of substances in and out of the cell.

Water-soluble Ions

Ions that dissolve in water, important in biological processes and the functioning of cells.

Lipid-soluble Molecules

Molecules that can dissolve in fats and oils, which allows them to easily pass through cell membranes that are made of lipids.