Lipids – Fats and Oils

Lipids – Good Fat / Bad Fat  Non polar  Derivative hydrocarbons (mostly C and H with some O)  Due to the large number of C- H bonds, they store more food energy than carbohydrates  They provide insulate bodies, protect plants from water loss, protect and cushion organs, insulate nerve tissue, build cell membranes and store energy for later use  Adipocytes are fat-storing cells – fat people don’t have adipocytes, just bigger ones

Triglycerides  One glycerol + three fatty acids  Dehydration synthesis occurs between each of the 3 hydroxyl functional groups in glycerol and the carboxyl group of the fatty acid  3 water molecules are the byproduct of this ester bond

Triglyceride Synthesis

Saturated and Unsaturated Triglycerides  Saturated fats are triglycerides with no double bonded carbons  They are solid at room temperature, dominate animal fats and can be synthesized by your body  Unsaturated fats are triglycerides with one or more double bonded carbons  They are liquid at room temperature and dominate vegetable fat such as olive oil  Humans cannot synthesize unsaturated fats – they must come from your diet

Phospholipids  A phospholipid has a glycerol backbone, two fatty acids and a polar phosphate- choline group

Phospholipid Bilayer  The polar / non-polar qualities of phospholipids allow them to spontaneously form membranes in water  They are the principal component of all cell membranes and can be saturated or unsaturated

Steroids

 4 carbon based ring structure  Non polar  Include cholesterol, vitamin D, testosterone, progesterone, estrogen, cortisone, bile salts  Vitamin D is synthesized from the interaction of UV radiation on subcutaneous cholesterol

Steroids

Pigments, Terpenes and Waxes  These are large, diverse groups that include chlorophyll (a pigment), natural rubber (a terpene) and beeswax (a wax)  They are all non polar and extremely stable – providing structural support and protection  In the case of pigments, they absorb photons of light