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LipidsLipids ELEMENTS:ELEMENTS: C, H(many), O C, H(many), O
(few)(few) H:O ratio much greater than H:O ratio much greater than
the carbohydratesthe carbohydrates
FUNTIONAL GROUPS:FUNTIONAL GROUPS: -OH, -COOH-OH, -COOH
MONOMERMONOMER: : Glycerol and Fatty AcidsGlycerol and Fatty Acids
SPECIAL BONDSPECIAL BOND: ester bond : ester bond (between the carboxyl and (between the carboxyl and
hydroxyl)hydroxyl)
Types of fatty acidsTypes of fatty acids Saturated: Saturated:
comes from animals comes from animals contain no double bondscontain no double bondsmore energymore energysolid (butter)solid (butter)
Unsaturated: Unsaturated: comes from plants comes from plants contains double bondscontains double bondsless energyless energyliquid (oils)liquid (oils)
HydrogenationHydrogenation
The adding of Hydrogens to a fatty acid molecule to make it more solid
Why?
To make food more solid for a longer shelf life and for more flavoring
Fatty acids: carboxylic acid Fatty acids: carboxylic acid + long hydrocarbon chain+ long hydrocarbon chain
CO
OHCH3
Carboxylic acid
Hydrocarbon chain
A saturated fatty acid
An unsaturated fatty acid
C
O
OH
CH3
© 2007 Paul Billiet ODWS
Fats and OilsFats and Oils
fatty acids + glycerol (1, 2 or 3 = mono , fatty acids + glycerol (1, 2 or 3 = mono , di or triglycerides)di or triglycerides)
C
O
OH
CH
3
C
O
OHCH
3
HO – CH2
HO - CH2
HO - CH Condensation reactions
© 2007 Paul Billiet ODWS
Two fatty acids joining glycerol Two fatty acids joining glycerol
= A diglyceride= A diglyceride
C
O
CH3
C
O
CH3
O - CH3
HO - CH3
O - CH
+ 2H20
© 2007 Paul Billiet ODWS
Lipid Polymers Lipid Polymers EXAMPLESEXAMPLES
Triglyceride: 3 F.A. Triglyceride: 3 F.A. and 1 glyceroland 1 glycerol
Phospholipids: 2 F.A. Phospholipids: 2 F.A. and 1 glyceroland 1 glycerol
Wax: long F.A. chain Wax: long F.A. chain and long alcohol chainand long alcohol chain
Steroids: testosterone, Steroids: testosterone, cholesterol, cholesterol, progesterone, estrogenprogesterone, estrogen
Lipid FunctionsLipid Functions
Energy storage (long term)Energy storage (long term) Protect and cushion organsProtect and cushion organs Insulation Insulation Storage of vitamins (A, D, E, Storage of vitamins (A, D, E,
K)K) Structural/building material Structural/building material
for bodyfor body
PhospholipidsPhospholipids
Chief component Chief component of cell membraneof cell membrane
Involved in fat Involved in fat storage and storage and transporttransport
CholesterolCholesterol Causes Causes
atherosclerosisatherosclerosis Hardening of the Hardening of the
arteriesarteries
Used to Used to synthesize synthesize hormones, hormones, clotting of bloodclotting of blood
Lipid TestsLipid Tests
Solubility test: fats do not dissolve Solubility test: fats do not dissolve in waterin water
Brown paper bag test: fats leave a Brown paper bag test: fats leave a translucent spottranslucent spot
Sudan IV test: turns red with the Sudan IV test: turns red with the presence of fatpresence of fat
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