 Also known as fats  Made of carbon, hydrogen, and oxygen  When your body breaks down lipids, it turns it into fatty acids and glycerol

 Muscles use this as a source of energy  2 types: › Saturated › Unsaturated

 Your body uses this to make glucose (which is the body’s main source of fuel)  Turns into body fat if not used

 Has lots of cholesterol  Comes from animal products (meat, dairy, etc.)  Is solid at room temperature  Is the worse of the two for you to have

 Vegetable oils  Is liquid at room temperature  Is healthier for you to have

 Fats  Phospholipids  Waxes  Steroids

 Made of glycerol & 3 fatty acids (triglyceride)  Function: › Keeps animals warm, provides long-term energy, protects internal organs

 Constructed of a head and 2 tails  Function: › Main part of a cell membrane

 Long chains of fatty acids linked to long chains of alcohols  Function: › Repels water › Important in water-proofing

 4 fused carbon rings  Function: › Act as chemical signals  estrogen / testosterone