Simple diffusion, osmosis and facilitated diffusion

Movement of molecules or ions from an area of high concentration to an area of low concentration, molecules move down the concentration gradient until a dynamic equilibrium is achieved

Simple diffusion occur with or without the presence of a plasma membrane

Lipid soluble molecules (fatty acids and glycerol), oxygen and carbon dioxide diffuse through the phospholipid bilayer as simple diffusion

Is a passive transport process that is similar to diffusion but it involves only water molecules

Refers to the net movement of water molecules from an area of high water potential to an area of low water potential randomly through a selectively permeable membrane

Is permeable to water but impermeable to some solutes such as sucrose molecules

The process of movement of lipid-insoluble molecules that are unable to pass through the phospholipid bilayer across the membrane with the aid of transport proteins (carrier or channel proteins)

Facilitated diffusion does not require energy because the transport proteins transport molecules down a concentration gradient