Pages 40 to 41 Chemical composition Carbon hydrogen

Pages 40 to 41

� Chemical composition �Carbon, hydrogen, oxygen and sometimes phosphorus � Building Blocks �Glycerol with 1 to 3 fatty acids �Phospholipids have glycerol, 2 fatty acids and a phosphate � Structure �Long chains (triglycerides and phospholipids) �Ring structure (steroids)

Fig. 5 -11 Fatty acid (palmitic acid) Glycerol (a) Dehydration reaction in the synthesis of a fat Ester linkage (b) Fat molecule (triacylglycerol)

Hydrophobic tails Hydrophilic head Fig. 5 -13 (a) Structural formula Choline Phosphate Glycerol Fatty acids (b) Space-filling model

Fig. 5 -15

� Examples �Fats �Oils �Waxes �steroids � Functions �Energy storage �Protection �Chemical messenger

� Common Property �Nonpolar/Hydrophobic �Does not dissolve in water Hydrophilic head WATER Hydrophobic WATER tail

� Saturated �All single Carbon to carbon bonds �Examples Animal fat Butter Lard �Not you very good for � Unsaturated �One or more double carbon to carbon bonds �Examples Plant oil – olive, corn, sunflower, etc… �Better for You

Fig. 5 -12 Structural formula of a saturated fat molecule Stearic acid, a saturated fatty acid (a) Saturated fat Structural formula of an unsaturated fat molecule Oleic acid, an unsaturated fatty acid (b) Unsaturated fat cis double bond causes bending