Ch5 Lipids
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Transcript of Ch5 Lipids
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8/8/2019 Ch5 Lipids
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AP Biology
Lipids: Fats & Oils
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AP Biology 2006-2007
Lipidslong term energy storage
concentrated energy
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AP Biology
Lipids
Lipids are composed of C, H, O
long hydrocarbon chains (H-C)
Family groups
fats
phospholipids
steroids
Do not form polymers big molecules made of smaller subunits
not a continuing chain
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8/8/2019 Ch5 Lipids
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AP Biology
Fats
Structure:
glycerol (3C alcohol) + fatty acid
fatty acid =
long HC tail with carboxyl (COOH) group head
dehydration synthesis
H2O
enzyme
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AP Biology
Building Fats
Triacylglycerol
3 fatty acids linked to glycerol
ester linkage = between OH & COOH
hydroxyl carboxyl
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AP Biology
Dehydration synthesis
dehydration synthesis
H2O
H2O
H2O
H O
enzyme
enzyme
enzyme
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8/8/2019 Ch5 Lipids
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AP Biology
Fats store energy
Long HC chain
polar or non-polar?
hydrophilic or hydrophobic?
Function:
energy storage
concentrated
all H-C!
2x carbohydrates
cushion organs
insulates body
think whale blubber!
Why do humans
like fatty foods?
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8/8/2019 Ch5 Lipids
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AP Biology
Saturated fats
All C bonded to H
No C=C double bonds
long, straight chain
most animal fats
solid at room temp.
contributes to
cardiovascular disease
(atherosclerosis)
= plaque deposits
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AP Biology
Unsaturated fats
C=C double bonds inthe fatty acids
plant & fish fats
vegetable oils liquid at room temperature
the kinks made by double
bonded C prevent the
molecules from packingtightly together
mono-unsaturated?
poly-unsaturated?
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8/8/2019 Ch5 Lipids
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AP Biology
Trans fats are a type of isomer
Fatty acid tails are hydrocarbons.Unsaturated fats have double bonds
between carbons.
Form follows function!
Trans fats are straight and solidify at
room temperature.
Cis (olive oil)
Trans (partially hydrogenated
vegetable oil)
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8/8/2019 Ch5 Lipids
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AP Biology
Phospholipids
Structure:
glycerol + 2 fatty acids + PO4 PO4 = negatively charged
Its just like apenguin
A head at one end& a tail
at the other!
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8/8/2019 Ch5 Lipids
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AP Biology
Phospholipids
Hydrophobic or hydrophilic?
fatty acid tails =
PO4 head =
split personality
interaction with H2O
is complex & very
important!repelled by water
attracted to water
Come here,No, go away!Come here,
No, go away!
hydrophobic
hydrophillic
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AP Biology
Phospholipids in water
Hydrophilic heads attracted to H2O
Hydrophobic tails hide from H2O
can self-assemble into bubbles
bubble = micelle
can also form a phospholipid bilayer
early evolutionary stage of cell?
bilayer
water
water
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AP Biology
Why is this important?
Phospholipids create a barrier in water
define outside vs. inside
they make cell membranes!
Tell themabout soap!
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8/8/2019 Ch5 Lipids
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AP Biology
Steroids
Structure:
4 fused C rings + ??
different steroids created by attaching different
functional groups to rings different structure creates different function
examples: cholesterol, sex hormones
cholesterol
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AP Biology
Cholesterol
Important cell component
animal cell membranes
precursor of all other steroids
including vertebrate sex hormones
high levels in blood may contribute to
cardiovascular disease
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AP Biology
Cholesterol
helps keep
cell membranes
fluid & flexible
Important component of cell membrane
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AP Biology
From Cholesterolp Sex Hormones
What a big difference a few atoms can make!
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8/8/2019 Ch5 Lipids
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AP Biology
Any Questions?
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AP Biology 2006-2007
Lets build some
Lipids!
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AP Biology 2007-2008
Ghosts of Lectures Past(storage)
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8/8/2019 Ch5 Lipids
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AP Biology
Phospholipids & cells
Phospholipids of cell membrane double layer = bilayer
hydrophilic heads on outside in contact with aqueous solution outside of
cell and inside of cell hydrophobic tails on inside
form core
forms barrier between cell &external environment
Tell themabout soap!