Glycerol forms the backbone of triglycerides and fatty acids. Triglycerides are composed of glycerol bonded to three fatty acid groups, and are classified as natural fats and oils. Fats are solid at room temperature while oils are liquid. Waxes are composed of a fatty acid bonded to a cetyl alcohol and are water resistant. Phospholipids are a complex lipid that form cell membranes and are made up of a fatty acid, glycerol, phosphate, and nitrogenous base. Lipids serve many important functions in the body including energy storage, cell membrane formation, hormone synthesis, and insulation.

1. Sripratha.S II M.sc., Applied Microbiology 1

2. Sripratha.S II M.sc., Applied Microbiology 2

3.  Glycerol is a tri-
hydroxy sugar
alcohol with 3
carbon atom and 3
hydroxyl group.
 It form the back
bone of fatty acids in
fats.
Sripratha.S II M.sc., Applied Microbiology 3

4. FattyacidstructureTypes
Sripratha.S II M.sc., Applied Microbiology 4

5.  A triglycerides is an
ester formed from
glycerol and 3 fatty
acid groups.
 Triglycerides are
classified as natural
fats and oils.
Sripratha.S II M.sc., Applied Microbiology 5

6.  3 Fatty acid + Glycerol
 They are triglycerides
 Difference between fats and oils are:
Fats are solid at room temperature, Oils are
liquid at room temperature.
Fats are mostly from animals, oils are mostly
from plants and fish.
Sripratha.S II M.sc., Applied Microbiology 6

7.  Wax are composed
of an ester of fatty
acid + cetyl alcohol.
 They are water
resistant, so they are
insoluble in water
 Eg: bees wax,
carnauba wax,
lanolin (wool wax)
Sripratha.S II M.sc., Applied Microbiology 7

8. Sripratha.S II M.sc., Applied Microbiology 8

9.  Poly unsaturated fatty acids (PUFAs) are
fatty acids that contain two or more
double bonds in their backbone.
 PUFAs and MUFAs are healthy fats, they
reduce risk of heart disease.
 PUFAs are present in plant, sea foods,
some nuts and seeds.
 2 major class of pufa are omega 3 and
omega 6
Sripratha.S II M.sc., Applied Microbiology 9

10.  Phospholipid are type of
complex lipid.
 Fattyacid + alcohol+
phosphate + nitrogenous
base.
 They are major
component of the
plasma membrane,
outermost membrane.
 2 types:
Glycerophospholipid
Sphingophospholipid.
Sripratha.S II M.sc., Applied Microbiology 10

11. Fatty acid + glycerol+
phosphate+Nitrogeous
base
Eg:
Phosphotedylethanola
mine-Cephalin
Phosphotedylcholin-
lecithin.
Fatty acid+ sphingosine
+ phospate+
Nitrogenous base.
Eg:
Sphingomyelin.
Sripratha.S II M.sc., Applied Microbiology 11

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 Amide + acyl group
 Sphingosine + fatty
acid.

13.  A glycolipid is a
carbohydrate attached to
lipid by glycosidic bond.
 fatty acid + sphingosine +
carbohydrate+ nitrogenous
base.
 3 types: Cerebrosides
Sulfatides
Gangliosides
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15.  Protein + fat which carry cholestrol
through blood stream.
 Role: adsorption and transfer of lipids
throughout the body.
 4 types: CM, VLDL, LDL, HDL
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16.  Hydrolyzed product of simple and
compound lipid is called Derived lipids.
Eg: steroids- sex hormone, bile acid.
sterols- phytosterol, zoosterol, mycosterol.
fat soluble vitamins – vitamin A,D,E,K.
Carotinoids – carotine, xanthophils.
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17.  Energy storage.
 Cell membrane.
 Mobilisation, Utilisation.
 Signal transmission.
 Hormone synthesis.
 Bile acid synthesis.
 Insulation and protection.
 Cell differentiation.
 Cholestrol formation.
 Maintain temperature.
 Prostaglandin formation.
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