carbon: lipids

• no true polymers - not big enough to be macromolecules
• hydrophobic based on molecular structure

  • has some polar bonds
  • consists of mostly hydrocarbons (VDW)
• fats:

  • large molecules assembled from smaller molecules via dehydration rxn
  • consists of gylcerol molecule joined with 3 fatty acids via ester linkage (hydroxyl + carboxyl group)
• saturated/unsaturated fats: refers to structure of hydrocarbon chains

  • no double bonds = saturated fatty acid (most animal fats)
  • flexible = can pack together = solid room temp
  • 1+ double bonds = unsaturated fatty acid (most plant + fish fats)
  • double bond = kink = less mobility = liquid room temp
  • every double bond in natural fatty acids are cis
  • trans fats: unsaturated fats are synthetically converted to saturated fats (adding hydrogens)
• function:

  • main: energy storage (long term)
  • 1g of fat stores 2x more energy than 1g of polysaccharides
• phospholipids:

  • essential for eukaryotic cells - make up cell membrane
  • 2 fatty acid tails (hydrophobic) attached to glycerol head (hydrophilic) via ester linkage
• steroids:

  • lipids characterized by carbon skeleton with 4 fused rings
  • distinguished by functional groups attached to it
  • ex: cholesterol in animals