bilayer membrane. polar hydrophilic head and nonpolar hydrophobic tail. cell membrane.

bilayer membrane cell phospholipid head tail hydrophilic hydrophobic lipid polar nonpolar bilayered structure medical diagram infographic biology science plasma liposome health body medicine chemistry protein molecule surface two sheet fluid transport protection barrier virus model channel osmosis diffusion cytoplasm cellular nutrition biochemistry cholesterol simple organism semipermeable vector ion vitro biological membranes parts membrane tail