lipids

why do lipids form an emulsion in the emulsion test?

lipids are insoluble in water but soluble in ethanol. when mixed with water, lipid droplets disperse, forming a white emulsion.

properties of lipids

• non-polar

• hydrophobic

• made of CHO

• insoluble in water but soluble in organic solvents e.g. alcohols

lipids as energy storage

lipids store twice as much energy per gram as carbs, making them an efficient energy store

lipids used for insulation

fat deposits under the skin provide thermal insulation in mammals (e.g. blubber in whales) which reduces heat loss

lipids for protection

lipids cushion vital organs, protecting them from physical damage

lipids used for waterproofing

waxes and oils prevent water loss in plants and animals (e.g. cuticle on leaves, sebum on skin)

lipids in membrane structure

phospholipids form biological membranes, controlling substance transport into and out of cells