2. 2
โข They are biological macromolecules
(polymers)that are made up of smaller
molecules(Monomers) ,lipids consists of a large
group of heterogeneous compounds.
โข They consist of Carbon(C) , Hydrogen(H) ,
Oxygen(O) atoms.
โข The solubility of lipids:
โข Lipids are insoluble in polar solvents as water but
they are soluble in non-polar solvents such as
benzene and carbon tetrachloride.
3. 3
Molecular structure of lipids:-
*lipids are formed from the union of :-
-Three fatty acids.
-One molecule of glycerol(an alcohol containing three hydroxyl groups(OH).
4. 4
Classification of lipids:-
*Lipids are classified ,according to their chemical ,structure, as the following.
Lipids
Simple Complex
Lipid
derivatives
5. 5
Simple lipids
Fats
solid formed by the
reaction of saturated
fatty acids with
glycerol
Oils
Liquid fats formed by
the reaction of
unsaturated fatty
acids with glycerol
Waxes
Formed by the reaction
of high molecular
weight fatty acids
with monohydric
alcohols
6. 6
Complex lipids
*They contain other elements like Carbon, Hydrogen, Oxygen,
Phosphorous and Nitrogen in their structure.
E.g. Phospholipids
*they are present in cell membrane in animals and plants Itโs similar
to the structure of fat but with phosphate (PO4) group and choline
replacing the 3rd fatty acid in fats .
7. 7
Importance of lipids
Obtaining
energy
*The energy obtained from lipids is more than the
energy obtained from the same amount of
carbohydrates.
*The body gets energy of Fat when thereโs no
carbohydrates.
Building cells *Lipids represent 5% of the organic materials involving
in the composition of cell.
*Phospholipids found in the structure of the cell wall.
Work as
thermal
insulator
*Lipids form an insulating layer under the skin in some
animals to maintain the body temperature.
