Phospholipids

• What is a phospholipid made up from?

  2 fatty acids, glycerol and a phosphate

  The fatty acids are known as a hydrophobic 'tail'- which orients itself away from water but readily mixes with fat.

  The phosphate molecule is known as a hydrophilic 'head', which interacts with water but not fat.
• Are phospholipids polar or non polar? Explain why


  Polar- they have two ends that behave differently.
• What happens when placed in water?

  They position themselves so that the hydrophilic heads are as close to the water as possible and hydrophobic tails are as far away from the water as possible.
• What is the function of the phospholipids in the membrane?


  Allows lipid-soluble substances to enter and leave the cell.

  Prevent water-soluble substances entering and leaving the cell.

  Makes the membrane flexible and self-sealing.

  Forms the lipid bilayer.