Diffusion Through Cell Membrane


  • As the cell membrane is composed mainly of a bilayer of phospholipid, lipid soluble molecules can diffuse through it very easily.
  • This is especially thrue for gases (O2, CO2 and N2) that are all lipid soluble.
  • In the cell, Oxygen diffuses in while carbon dioxide diffuses out, down their respective concentration gradients.
    • Water, though not lipid soluble, can diffuse easily as it is a very small molecule and literally cuts through the membrane.