Regents Biology Lipids Hydrophobic molecules Do NOT consist of polymers Function: energy storage cell membrane protection - cushions organs insulates body
Regents Biology Structure of Fat
Regents Biology What are lipids composed of? 1 glycerol + 3 fatty acids lipids (triglycerides) Vary in length and number and location of double bonds
Regents Biology How are lipids made and broken down?
Regents Biology How are lipids made? Broken down?
Regents Biology Saturated Fats Mostly animal fats solid at room temperature Saturated with hydrogen All single bonds Can be tightly packed Limit the amount in your diet
Regents Biology Unsaturated fats Plant, vegetable & fish fats (oils) liquid at room temperature the fat molecules don’t stack tightly together Double bond causes a kink Better choice in your diet
Regents Biology Saturated vs. Unsaturated Examples saturatedunsaturated Meat Butter Ice Cream Cookies Animal Fat Olive oil Canola Oil Avocado Nuts Seafood Soy
Regents Biology Other lipids in biology Cell membranes are made out of phospholipids 2 fatty acid tails & a phosphate group heads are on the outside touching water “like” water (hydrophilic) tails are on inside away from water “scared” of water (hydrophobic) forms a barrier between the cell & the outside
Regents Biology 10 Phospholipid structure CH 2 O P O O O CH CH 2 OO C O C O Phosphate Glycerol (a) Structural formula (b) Space-filling model Fatty acids (c) Phospholipid symbol Hydrophobic tails Hydrophilic head Hydrophobic tails – Hydrophilic head CH 2 Choline + Figure 5.13 N(CH 3 ) 3
Regents Biology The structure of phospholipids Results in a bilayer arrangement found in cell membranes Hydrophilic head WATER Hydrophobic tail Figure 5.14
Regents Biology Other lipids in biology Steroids, Ex: Cholesterol Carbon skeleton of 4 fused rings good molecule in cell membranes make hormones from it including sex hormones but too much cholesterol in blood may lead to heart disease HO CH 3 H3CH3C
Regents Biology Other lipids in biology Waxes Bees, ears, shiny leaves, shiny feathers, hair Repels water For protection