Lipids Fats Oils AP Biology Lipids AP Biology

Lipids: Fats & Oils AP Biology

Lipids ________________________ AP Biology 2006 -2007

Lipids § Lipids are composed of C, H, O u ______________ § “Family groups” _________________ u § ______________ big molecules made of smaller subunits u not a continuing chain u AP Biology

Fats § Structure: u __________________ § fatty acid = long HC “tail” with carboxyl (COOH) group “head” enzyme H 2 O dehydration synthesis AP Biology

Building Fats § Triacylglycerol 3 fatty acids linked to glycerol u ________ = between OH & COOH u hydroxyl AP Biology carboxyl

Dehydration synthesis H 2 O dehydration synthesis enzyme H 2 O enzyme AP Biology H 2 O

Fats store energy § Long HC chain Why do humans like fatty foods? polar or non-polar? u hydrophilic or hydrophobic? u § Function: u _________ § concentrated w all H-C! § 2 x carbohydrates _________________ u AP Biology § think whale blubber!

Saturated fats § All C bonded to H § No C=C double bonds ____________________ u § contributes to cardiovascular disease (atherosclerosis) = plaque deposits AP Biology

Unsaturated fats § C=C double bonds in the fatty acids ______________________ u § the kinks made by double bonded C prevent the molecules from packing tightly together AP Biology mono-unsaturated? poly-unsaturated?

Saturated vs. unsaturated _______________ AP Biology

Phospholipids § Structure: u glycerol + 2 fatty acids + PO 4 § PO 4 negatively charged It’s just like a penguin… A head at one end & a tail at the other! AP Biology

Phospholipids § Hydrophobic or hydrophilic? fatty acid tails = ___________ u PO 4 head = ___________ “attracted to water” u split “personality” u Come here, No go away! interaction with H 2 O is complex & very important! AP Biology “repelled by water”

Phospholipids in water § ____________________________________ u can self-assemble into “bubbles” § bubble = “micelle” § can also form a _____________ § early evolutionary stage of cell? water bilayer AP Biology water

Why is this important? § Phospholipids create a barrier in water define outside vs. inside u they make ____________ u 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 AP Biology

Cholesterol § Important cell component ________________________________ u § including vertebrate sex hormones u AP Biology high levels in blood may contribute to cardiovascular disease