Upload
annice-simmons
View
217
Download
0
Embed Size (px)
Citation preview
AP Biology
Lipids: Fats & Oils
AP Biology
Lipids Lipids are composed of Carbon, Hydrogen, and
small amts of Oxygen long hydrocarbon chains (H-C)
Do not form polymers They are big molecules made of smaller subunits not a continuing chain
2006-2007 AP Biology
Lipid Functionslong term energy storage
InsulationWaterproofing
Hormone Production
AP Biology
Fats Structure:
Fats, Oils and Waxes are made of a Glycerol molecule (3-Carbon alcohol) + fatty acid fatty acid =
long Hydrogen/Carbon “tail” with carboxyl (COOH) group head
dehydration synthesis
H2O
enzyme
AP Biology
Building Fats Triacylglycerol
3 fatty acids linked to glycerol ester linkage = between OH & COOH…links a
glycerol to fatty acids. hydroxyl carboxyl
AP Biology
Dehydration synthesis
dehydration synthesis
H2O
H2O
H2O
H2O
enzyme
enzyme
enzyme
AP Biology
Fats store energy Long Fatty Acid Tail
It is non-polar Hydrophobic (repels water)
Function: energy storage
2x what is given in carbohydrates cushion organs insulates body
think whale blubber!
AP Biology
Saturated fatty acids All Carbon bonded to Hydrogen No C=C double bonds
long, straight chain most animal fats solid at room temp.
contributes to cardiovascular disease = plaque deposits
AP Biology
Unsaturated fatty acid tail C=C double bonds in the fatty acids
plant & fish fats vegetable oils liquid at room temperature
the kinks made by doublebonded Carbon prevent the molecules from packing tightly together
AP Biology
Saturated vs. unsaturatedsaturated unsaturated
AP Biology
Phospholipids Structure:
Made of a glycerol molecule + 2 fatty acids + PO4 (phosphate group) PO4 = negatively charged
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”
hydrophobic
hydrophillic (attracted to water)
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
AP Biology
Why is this important? Phospholipids create a barrier in water
define outside vs. inside they make cell membranes!
AP Biology
Steroids Structure:
4 fused Carbon rings + One Functional Grp?? different steroids created by attaching different
functional groups to rings Important: different structure = different function
examples: cholesterol, sex hormones
cholesterol
AP Biology
Cholesterol- type of Steroid Important cell component
animal cell membranes
- keeps fatty acid tails from sticking together precursor of all other 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!
AP Biology
LIPIDS All Lipids are INSOLUBLE in water!