Fig. 2.15

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Fig. 2.15
Fats (lipids)
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FUNCTIONS
Fats are mostly for storing energy long term in
an organism.
Fats also serve to Insulate the body Pad and
protect organs Store fat-soluble vitamins
(ADEK) Form steroid hormones (testosterone,
estrogen etc.) Structurally form cell membranes.
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Various Fats
Neutral Fats
Phospholipids
Sterol Lipids
Although there are a variety of types of
fats/lipids, and structurally they may look very
different and functionally they may serve very
different purposes one thing they have in common
is that they are all HYDROPHOBIC dont mix with
water.
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Fig. 2.22
NEUTRAL Fats
Formed when a Glycerol Molecule undergoes a
dehydration synthesis reaction with Fatty Acid
Chains. If only one chain joins on
Monoglyceride If two chains join on
Diglyceride If three chains join on Triglyceride
These molecules are used to store energy, as the
fatty acids can be burned as fuel by the organism.
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Fig. 2.23ab
PHOSPHOLIPIDS
Formed when a Glycerol combines with two
hydrophobic fatty acid chains, but on the third
site on the glycerol a polar (hydrophilic)
phosphate group binds on. So part of the
phospholipid love water while the rest of the
molecule avoids water.
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Fig. 2.23c
When two layers of Phospholipids form, they take
up the following orientation. This Phospholipid
Bilayer forms the main portion of a cells
membrane.
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Cell membrane model
8
Fig. 2.24
STEROL LIPIDS
Recognized by having four carbon rings (yellow in
molecules below) fused together in the pattern
below.
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Sterol Lipid Functions
Cholesterol is used to structurally firm up the
cell membrane
Cholesterol
Most Sterol Lipids form Hormone messengers in the
body, while other sterol lipids are used as
structural building molecules