Principles Module 9

Lipids molecular model on YouTube


  • Describe the characteristics of lipids
  • Describe the structure of lipids
  • Explain why phospholipids form bilayers
  • Relate the structure of phospholipids to cell structure and function

Key points

  • lipids don’t mix well with water because they are nonpolar
  • phospholipids have a hydrophobic and hydrophilic end, making them unique
  • phospholipids form bilayers due to their structure, making up membranes
  • other examples of lipids
    • steroids are an important class of lipid
    • fats (triglycerides) are energy-storing compounds
    • pigments like chlorophylls

In-class activities

  • identify all the sources of lipids in you diet over the last 24 h
  • where in your body do you think they are being used