Phospholipids

• what do phospholipids form?

  a barrier to dissolved substances
• what do phospholipid molecules have?

  a head and a tail
• describe the head of a phospholipid?

  hydrophilic
• describe the tail of a phospholipid ?

  hydrophobic
• what do the molecules AUTOMATICALLY arrange themselves into?

  a bilayer

  • the heads face out towards the water on either side of the membrane
• describe the centre of the bilayer?


  hydrophobic
• why is the centre of the bilayer hydrophobic?

  So the membrane doesn't allow water-soluble substances through it- it acts as a barrier to these dissolved substances
• give an example of water-soluble substances?


  ions