Lipids

Lipids are: Greasy, oily compounds Hydrophobic (no affinity for water) Mostly consist of nonpolar bonds Functions: Energy storage, membrane structure, & coatings

3 Families of Lipids: 1. Fats 2. Phospholipids 3. Steroids

Fats Made up of Glycerol and 3 Fatty Acids Fatty acid & Glycerol linkage is between the hydroxyl & carboxyl Glycerol

Saturated Fats Contain fatty acids without double bonds in their carbon skeletons Solid at room temp. Animal Fats- Lard, bacon, grease, butter Contribute to cardiovascular disease (plaque develops in arteries) Atherosclerosis

Unsaturated Fats Contain fatty acids WITH double bonds Liquid at room temp. because double bonds take up more space so molecules can’t cram in tightly Plant Fats ex. Olive oil, vegetable oil, peanut oil

Monounsaturated fatty acid has One double bond Polyunsaturated fatty acids have 2 or more double bonds. What is a hydrogenated oil? An unsaturated fat synthetically converted to a saturated fat by adding hydrogens (I.e. margarine) These are BAD for you!

Mono-unsaturated Fats

Polyunsaturated Fats

Hydrogenated Oils

Major function of fats: ENERGY - long term energy needs Human Adipose Cells: expand or shrink; you never lose them even when you lose weight

Phospholipids Made of glycerol, 2 fatty acids, & a negatively charged phosphate group and an additional chemical group which is usually attached to the phosphate ambivalent towards water - Amphipathic

Phospholipid structure: HEADS (glycerol & phosphates) - Hydrophilic TAILS (Fatty acid chains) - Hydrophobic

Phospholipid Bilayer Makes up cell membranes Phosphate Heads = hydrophilic Lipid Tails = hydrophobic

Steroids 4 connected carbon rings with functional groups attached Ex. Cholesterol - common component fo cell membrane in ANIMALS (Keeps cells from freezing) Ex. Waxes - long chain fatty acids & alcohols with carbon rings; coats plant parts

Trans Fats Used extensively in packaged foods as preservatives - hydrogenated oils. The WORST kind of fat for you!

Put in your NOTECARDS: 1. The structure of both Glycerol & Fatty Acids 2. The difference between Saturated and Unsaturated Fats along with the properties of each 3. The structure of a Phospholipid 4. The structure of a Steroid 1 NOTECARD