B1.1.11

• Triglycerides are used for energy storage in plants and animals.
• The properties of triglycerides make them particularly suitable for long term energy storage:

  • chemically very stable - energy is not lost over time
  • immiscible with water - naturally form droplets in the cytoplasm
  • release twice as much energy/gram in cell respiration as carbohydrate - so enough energy can be stored in half the body mass
  • poor conductors of heat - they can be used as a thermal insulator
  • liquid at body temperature - they act as shock absorber
• Thermal insulation is needed the most by animals that live in cold habitats. These animals have thick layers of subcutaneous adipose tissue.
• Functions of triglycerides:

  • energy source
  • energy store
  • insulation
  • buoyancy
  • protection