B1.1.13

• Steroids are a group of lipids with molecules similar to sterol.
• Steroids can be identified using these features:

  • four fused rings of carbon
  • three cyclohexane rings and one cyclopentane ring
  • 17 carbon atoms in total in the rings
• Steroids are mostly hydrocarbon and therefore hydrophobic. This allows them to pass through the phospholipid bilayers and enter or leave cells.
• Cholesterol is an example of a sterol.