ap biology 2006-2007 lipids oils fats. ap biology lipids: fats & oils
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2006-2007 AP Biology
Lipids
OilsFats
AP Biology
Lipids: Fats & Oils
AP Biology
Lipids Lipids are composed of C, H, O
Not considered polymers-no subunits
“Family groups” Fats Phospholipids Steroids
Polymers big molecules made of smaller subunits not a continuing chain
AP Biology
Fats Structure:
Glycerol and fatty acids fatty acid =
long HC “tail” with carboxyl (COOH) group “head”
dehydration synthesis
H2Oenzyme
AP Biology
Building Fats Triacylglycerol
3 fatty acids linked to glycerol Ester linkage = between OH & COOH
hydroxyl carboxyl
AP Biology
Dehydration synthesis
H2O
H2O
H2O
H2O
enzyme
enzyme
enzyme
dehydration synthesis
AP Biology
Fats store energy Long HC chain
polar or non-polar? hydrophilic or hydrophobic?
Function: Store Energy
concentrated all H-C!
2x carbohydrates Cushioning Insulates
think whale blubber!
AP Biology
Saturated fats All C bonded to H No C=C double bonds
Solid at Room Temp. Butter Lard
contributes to cardiovascular disease (atherosclerosis) = plaque deposits
AP Biology
Unsaturated fats C=C double bonds in
the fatty acids One or more double bonds Plant Fats Liquid at Room Temp.
the kinks made by doublebonded C prevent the molecules from packing tightly together
AP Biology
Saturated vs. unsaturated_______________ _______________
AP Biology
Phospholipids Structure:
glycerol + 2 fatty acids + PO4
PO4 negatively charged
AP Biology
Phospholipids Hydrophobic or hydrophilic?
fatty acid tails = Hydrophobic PO4 head = Hydrophilic split “personality”
interaction with H2O is complex & very important! “repelled by water”
“attracted to water”
AP Biology
Phospholipids in water Tails repelled by water Heads attracted to water
can self-assemble into “bubbles” bubble = “micelle” can also form a Bilayer early evolutionary stage of cell?
bilayer
water
water
AP Biology
Why is this important? Phospholipids create a barrier in water
define outside vs. inside they make Cell Membrane
AP Biology
Steroids Structure:
4 fused C rings + ?? different steroids created by attaching different
functional groups to rings different structure creates different function
What are some examples:
cholesterol
AP Biology
Cholesterol Important cell component
Part of the cell membrane Used to make other types of steroids
including vertebrate sex hormones 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!
2006-2007 AP Biology
Let’s build some
Lipids!