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
AP Biology 2006-2007 Lipid Functions long term energy storage Insulation Waterproofing 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 H2OH2O 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 H2OH2OH2OH2OH2OH2OH2OH2O 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 double bonded Carbon prevent the molecules from packing tightly together
AP Biology Saturated vs. unsaturated saturatedunsaturated
AP Biology Phospholipids Structure: Made of a glycerol molecule + 2 fatty acids + PO 4 (phosphate group) PO 4 = negatively charged
AP Biology Phospholipids Hydrophobic or hydrophilic? fatty acid tails = PO 4 head = split “personality” interaction with H 2 O is complex & very important! “repelled by water” “attracted to water” hydrophobic hydrophillic (attracted to water)
AP Biology Phospholipids in water Hydrophilic heads “attracted” to H 2 O Hydrophobic tails “hide” from H 2 O can self-assemble into “bubbles” bubble = “micelle” can also form a phospholipid bilayer early evolutionary stage of cell? bilayer 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!