Fatty acids

Determining if fatty acid

• carboxylic acid

• long hydrocarbon (CH, CH2, CH3) chain

• 12-20 carbons in molecule

• fit closer together when unsaturated

Types of fatty acids:

• triacylglycerol/triglyceride : lipid in plants and animals

  • most important in long term energy storage

  • molecule of glycerol

  • to make:

    • esterification of : carboxylic acid and alcohol —→ ester + H2O

    • reactants: 3 fatty acids (can be different fatty acids) + 1 glycerol

    • product: 1 triacylglycerol + 3 H2O molecules

Melting point

* melting point increases with more carbons in molecule

• saturated fatty acids have highest melting points

• unsaturated fatty acids have lower mp’s than saturated fatty acids

• trans- unsaturated fatty acids have lower mp than unsaturated fatty acids

• cis- unsaturated fatty acids have lowest mp compared to trans unsaturated fatty acids