Cell membrane blocking particles, illustration 插畫檔

Illustration of the phospholipid bilayer that forms the cell membrane around blocking large particles. The phospholipid molecules line up in two sheets, with the hydrophilic tails projecting inward and their polar head groups projecting outwards. The hydrophilic surface on both sides of the membrane is the point of contact for molecules leaving or entering the cell. Large molecules are often too big to pass directly through the lipid bilayer of the cell membrane, so they require transport proteins or endocytosis to enter the cell