Examples fats – butter, lard (solid @ room temp) Oils - liquid @ room temp waxes hormones

1. LIPIDS: Concentrated energy molecules • Examples • fats – butter, lard (solid @ room temp) • Oils - liquid @ room temp • waxes • hormones • sex hormones • testosterone (male) • estrogen (female)

2. Lipids • Function: 1.energy storage • very concentrated • twice the energy as carbohydrates! • (higher in calories) 2.cell membrane 3.cushions organs 4. insulates body • think whale blubber!

3. Structure of Fat not a chain (polymer) = just a “big fat molecule” fatty acids (3) glycerol

4. Saturated fats • Most animal fats • solid at room temperature • Limit the amount in your diet • contributes to heart disease • deposits in arteries Straight molecule ALL single C-C bonds

5. Unsaturated fats • Plant, vegetable & fish fats • liquid at room temp • the fat molecules don’t stack tightly together • Better choice in your diet Molecule is bent Double and/or triple C=C bond(s) present

6. Other lipids in biology • Cholesterol • good molecule in cell membranes • “glue”; helps to stabilize membrane • make hormones from it • including sex hormones • but too much cholesterol in blood may lead to heart disease plaque

7. Other lipids in biology • Cell membranes are made out of lipids • phospholipids • heads are on the outside touching water • “like” water • tails – (2) are on inside away from water • “scared” of water (oil and water don’t mix) • forms a barrier between the cell & the outside outside bilayer inside