Triglyceride Formation
Lipids
- Lipids are macromolecules that contain carbon, hydrogen and oxygen atoms. Unlike carbohydrates, lipids contain a lower proportion of oxygen
- Lipids are non-polar and hydrophobic (insoluble in water)
- Triglycerides are a kind of lipid that forms the main component of fats and oils
- Lipids play an important role in energy yield, energy storage, insulation and hormonal communication
Triglycerides
- Are non-polar, hydrophobic molecules
- The monomers are glycerol and fatty acids
- Glycerol is an alcohol (an organic molecule that contains a hydroxyl group bonded to a carbon atom)
- Fatty acids contain a methyl group at one end of a hydrocarbon chain known as the R group (chains of hydrogens bonded to carbon atoms, typically 4 to 24 carbons long) and at the other is a carboxyl group
- The shorthand chemical formula for a fatty acid is RCOOH
The basic structure of a triglyceride
Function of lipids
- Triglycerides are fats and oils
- Fatty acid and glycerol molecules are the components that make up triglycerides
- Fats and oils have a number of important functions in organisms: energy storage, insulation, buoyancy, and protection
Forming an ester bond: condensation reaction
- Triglycerides are formed by esterification
- An ester bond forms when the hydroxyl (-OH) group of the glycerol bonds with the carboxyl group (-COOH) of the fatty acid
- The formation of an ester bond is a condensation reaction
- For each ester bond formed a water molecule is released
- Three fatty acids join to one glycerol molecule to form a triglyceride
- Therefore for one triglyceride to form, three water molecules are released
Formation of a triglyceride from a glycerol molecule and three fatty acid molecules by the process of esterification