LIPIDS
Lipids are macromolecules
by gauri
Contain the elements CHO
They are non-polar thus do not dissolve in water
Fatty acids + alchols ---> fats, oils
COOH
OH
Fatty acids
Head of the molecule ----> COOH : carboxyl group
A hydrocarbon chain is the tail and is attached to the
carboxyl group
The tails can be saturated ---- no carbon carbon double
bonds
The tails acn also be unsaturated ---- conatin a carbon
carbon double bond.
1. monounsaturated - only one c-c duoble bond
2. polyunsaturated - more than one c-C double bond
Unsaturated bonds often cause the chain to bend pushing
the triglyceride. This also lowers the melting point thus
those lipids with unsaturated fatty acids form oils. Those
with saturated fatty acids form fats.
Animal lipids are often fats
Plant lipis are often oils ( sunflower oil )
Glycerol is an alcohol as it contains
the OH group in one glycerol
moleculer there are three hydroxyl
groups (OH)
Ester bonds : acid + alcohol
-COO- ester linkage
This is a condensation reaction
Triglycerides
1 glycerol + 3 fatty acids
Condensation reaction
3 ester bonds
Soluable in ethanol
Are hydrophobic
Function
Excellent source of energy. Provide more energy than carbohydrates of the mass.
Are insulators
Provide buoyancy
When oxidised they form carbon dioxide and water. Therefore when respired lipids provide
water for dessert animals.
Phospholipids
1 glycerol + 2 fatty acids tails + Phosphate molecule head
Condensation reaction
Phosphate molecule is hydrophyllic as is polar with a slight neagtive charge
Phospholipids are a main constituent of the cell mebrane as they form a
phospholipid bilayer there.
Hyrdrohphyllic heads form two rows on the outside and hydro[phyllic talis are
sheltered in the middle