macros: lipids

• lipids: energy storage, component of membranes, chemical signaling. C:H:O but fewer –OH and more C-H bonds than carbs
• lipids are nonpolar and insouble in water
• fats: energy source and insulation (adipose tissue). the most common is triglycerides (1 glycerol and 3 fatty acids)
• fatty acids: saturated fats have single bonds and can fit closely together due to VDW forces. solid at room temp.
• fatty acids: unsaturated fatty acids have a double bond and cannot fit as close b/c VDW forces are weakened due to a kink in the chain. liquid at room temp.
• phospholipids: 1 glycerol attached to 2 fatty acids(hydrophobic) and 1 PO4(hydrophilic).
• phopholipids: form micelles in water with tails turned inwards

  
• steroids: function in membranes. composed of 4 hydrophobic rings and various functional groups. in bones, digestion, and hormones
• waxes: hydrophobic and composed of fatty acids connected to OH- or carbon rings. waterproof coatings on leaves, fruit, feathers,

  honeycombs