Lipids

Testing for lipids

  • emulsion test

  • emulsion test

Lipids

  • non polar

  • Not water soluble

  • Made up of C H and O

  • Macromolecules

    • large complex molecules not built from monomers

Functions of lipids

  • protection of vital organs

  • Prevent evaporation or for waterproofing plants and animals

  • Insulate the body

  • Form the myelin sheath around some neurones

  • As a water source

  • As a component of cell membranes

  • Hormone production

  • Buoyancy for aquatic animals

Triglycerides

  • form a lipid

  • triglyceride

  • triglyceride formation

Saturated and unsaturated fatty acids

  • The fatty acids attached to a glycerol can be saturated or unsaturated

  • Affects structure

  • saturated vs unsaturated fatty acids

Phospholipids

  • one fatty acid chain replaced by one phosphate group

  • Hydrophilic head and hydrophobic tail

  • Functions

    • form monolayers with water

    • bilayers like cell membranes

Sterols

  • steroid alcohols

  • Eg cholesterol

    • made in the liver and intestines

    • maintains stability of cell membranes

    • involved in vitamin D, steroid hormones and bile production