Lipids - Springfield Public Schools · Lipids: Fats & Oils AP Biology Lipids long term energy...
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1 Division Ave. High School Ms. Foglia AP Biology AP Biology Lipids: Fats & Oils AP Biology Lipids long term energy storage concentrated energy AP Biology Lipids § Lipids are composed of C, H, O u long hydrocarbon chains (H-C) § Family groups u fats u phospholipids u steroids § Do not form polymers u big molecules made of smaller subunits u not a continuing chain
Transcript of Lipids - Springfield Public Schools · Lipids: Fats & Oils AP Biology Lipids long term energy...
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Division Ave. High School Ms. Foglia AP Biology
AP Biology
Lipids: Fats & Oils
AP Biology
Lipids long term energy storage
concentrated energy
AP Biology
Lipids § Lipids are composed of C, H, O
u long hydrocarbon chains (H-C) § �Family groups�
u fats u phospholipids u steroids
§ Do not form polymers u big molecules made of smaller subunits u not a continuing chain
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Division Ave. High School Ms. Foglia AP Biology
AP Biology
Fats § Structure:
u glycerol (3C alcohol) + fatty acid § fatty acid =
long HC �tail� with carboxyl (COOH) group �head�
dehydration synthesis
H2O
enzyme
AP Biology
Building Fats § Triacylglycerol
u 3 fatty acids linked to glycerol u ester linkage = between OH & COOH
hydroxyl carboxyl
AP Biology
Dehydration synthesis
dehydration synthesis
H2O
H2O
H2O
H2O
enzyme
enzyme
enzyme
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Division Ave. High School Ms. Foglia AP Biology
AP Biology
Fats store energy § Long HC chain
u polar or non-polar? u hydrophilic or hydrophobic?
§ Function: u energy storage
§ concentrated w all H-C!
§ 2x carbohydrates u cushion organs u insulates body
§ think whale blubber!
Why do humans like fatty foods?
AP Biology
Saturated fats § All C bonded to H § No C=C double bonds
u long, straight chain u most animal fats u solid at room temp.
§ contributes to cardiovascular disease (atherosclerosis) = plaque deposits
AP Biology
Unsaturated fats § C=C double bonds in
the fatty acids u plant & fish fats u vegetable oils u liquid at room temperature
§ the kinks made by double bonded C prevent the molecules from packing tightly together
mono-unsaturated? poly-unsaturated?
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Division Ave. High School Ms. Foglia AP Biology
AP Biology
Saturated vs. unsaturated saturated unsaturated
ü
AP Biology
Phospholipids § Structure:
u glycerol + 2 fatty acids + PO4
§ PO4 = negatively charged
It�s just like a penguin…
A head at one end & a tail
at the other!
AP Biology
Phospholipids § Hydrophobic or hydrophilic?
u fatty acid tails = u PO4 head = u 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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Division Ave. High School Ms. Foglia AP Biology
AP Biology
Phospholipids in water § Hydrophilic heads �attracted� to H2O § Hydrophobic tails �hide� from H2O
u can self-assemble into �bubbles� § bubble = �micelle� § can also form a phospholipid bilayer § early evolutionary stage of cell?
bilayer
water
water
AP Biology
Why is this important? § Phospholipids create a barrier in water
u define outside vs. inside u they make cell membranes!
Tell them about soap!
AP Biology
Steroids § Structure:
u 4 fused C rings + ?? § different steroids created by attaching different
functional groups to rings § different structure creates different function
u examples: cholesterol, sex hormones
cholesterol
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Division Ave. High School Ms. Foglia AP Biology
AP Biology
Cholesterol § Important cell component
u animal cell membranes u precursor of all other steroids
§ including vertebrate sex hormones u high levels in blood may contribute to
cardiovascular disease
AP Biology
Cholesterol
helps keep cell membranes fluid & flexible
Important component of cell membrane
AP Biology
From Cholesterol → Sex Hormones § What a big difference a few atoms can make!
