Structure of Eukaryotic Cells


Cell-surface membrane

  • Controls the movement of substances in and out of cell
  • Phospholipds form a bilayer
    • Hydrophillic heads point outwards- attracted by water on both sides
    • Hydrophocic heads point inwards- repelled by water on both sides
    • Prevent water-soluble substances from entering/ leaving cell
    • Make membrance flexible and self-sealing
  • Proteins embedded in phospholipd bilayer
    • Give mechanical support/ act as receptors for molecules (e.g. hormones) with glycolipids 
    • Protein channels allow water-soluble ions to diffuse across membrane
    • Carrier proteins bind to ions or molecules (e.g. glucose) and change shape to move them across membrane
  • Cholesterol
    • Hydrophobic so prevent loss of water/ dissolved ions from cell
    • Pull together fatty acid tail to reduce their movement
    • Make membrane less fluid at high temperatures
  • Glycolipids
    • Carbohydrate protion extends into watery environemnt outside cell to act as a receptor
    • Help cells attach to each other 
  • Glycoproteins
    • Act as receptors
    • Allow cells to recognise each other (e.g. lymphocytes recognise an organism's own cells)


  • Contains genetic material and controls cell activities
  • Nuclear envelope
    • Double membrane surrounding nucleus
    • Controls the movement…


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