Triglycerides store concentrated long-term energy because they are insoluble, stable, compact, and rich in energy-yielding carbon-hydrogen bonds within adipose tissue.
Coverage 2013–2025 · Updated 15 Jul 2026
Triglycerides in adipose tissue provide concentrated long-term energy storage and thermal insulation.
Their many reduced C–H bonds yield more energy per unit mass than carbohydrate when oxidized. Hydrophobic triglycerides are stored without a large hydration shell and have little osmotic effect; oxidation also produces metabolic water.
Adipose tissue beneath the skin slows heat transfer, helping an endotherm maintain a stable body temperature. Thick fat layers are especially useful in cold or aquatic habitats and can also cushion organs or aid buoyancy.
A marine mammal can carry a compact energy reserve in blubber while the same adipose layer reduces heat loss to cold water.
Triglycerides form storage droplets, not bilayers: three hydrophobic tails and no strongly polar phosphate head make them unsuitable as the basic membrane sheet.
This objective is assessed through structured response, commonly using Explain / Outline / State.
Explain / Outline / State
Build the answer around this relationship: Triglycerides store more energy per gram than carbohydrates.
Saying lipids are more efficient because they are easier to transport than carbohydrates.
Representative question
Outline the use of lipids to store energy in humans.
B1.1 becomes easy when every answer follows structure -> property -> function. Carbon skeletons and functional groups create molecular diversity. Condensation builds larger molecules and hydrolysis breaks them. Alpha-glucose stores energy as starch and glycogen; beta-glucose forms strong cellulose. Surface carbohydrates enable recognition. Lipids are hydrophobic, triglycerides store energy, phospholipids self-assemble into bilayers, and steroids cross membranes because they are mostly non-polar.
