lipids

triglycerides structure

glycerol and three fatty acids

phospholipids structure

phosphate group, glycerol and two fatty acids

formation of triglycerides

3 condensation reaction between 3 fatty acids and glycerol forming 3 ester bonds

saturated fatty acids

hydrocarbon chain had only single bonds between carbons

unsaturated fatty acids

hydrocarbon chain has at least one double bond between carbons

triglycerides properties

-energy store

-act as a metabolic water source, release water when oxidised (due to high ratio of h to o)

-large and hydrophobic, insoluble in water, not affect water potential

-low mass, can be stored without increasing mass

phospholipid properties

• hydrophilic head

• attracts water and repels fats due to charge

• hydrophobic tail repels water but mixes with fats