CH 10 - Lipids

CH 10 - Lipids

1. Fatty acids

   • hydrocarbons that are used to make fats and oils 4 to 36 carbons
   • Saturated
     • Unbranched and no double bonds
   • Unsaturated
     • Contains double bonds Usually between 9 and 10
     • Omega 3
       • Contains a double bond every 3 carbons Need to supply by diet
   • Effect of Chains
     • Longer chains causes lower solubility in water The more the double bonds in the chain the lower the solubility
   • Effects of Melting point
     • When it is saturated it is a solid - higher melting point When it is unsaturated it is a oil - lower melting point
   • Lipoproteins
     • High is good Low is bad

2. Fatty Acid Esters of Glycerol

   • Triacyglycerols or triglycerides 3 fatty acids with a ester linage with a single glycerol Nonpolar due to ester linkages even though hydroxyls and carboxylates are polar Allows for twice as much energy than carbohydrates Lighter than other energy due to no water
   • Lipases
     • Catalyze the hydrolysis of stored triglycerides which release datty acids for export to sites that need the energy

3. Trans Fat

   • Hydrogenation to increase shelf life Found to have an effect to the body negatively

4. Waxes

   • Used for water proofing and lubrication

5. Phospholipids

   • polar head with hydrophobic tail linked by phosphodiester
   • Glycolipids
     • Version without the phosphate and instead it has a sugar
   • Lysophospholipids
     • Made by phosphoslipases which remove one of the two fatty acids

6. Glycerophospholipid

   • C-1 has a fatty acid by ester C-2 has a glycerol by ester C-3 has a polar alcohol attached by a phosphodiester
   • Ether-linked Fatty acid
     • Can have a double bond between C-1 and C-2 instead Called a plasmalogens Seen in the heart which is thought to have resistance to phospholipases One known example is platelet activating factor released by basophils

7. Galactolipids

   • one or two galactose are connected by glycosidic linkage to C-3 Usually in vascular plants and make up most of it

8. Archaea Lipids

   • Glycerol dialkyl glycerol tetraethers
     • Has R configuration of this type instead of S that is in bacteria and eukaryotes

9. Sphingolipids

   • Like glycerophospholipids, but no glycerol but instead amide (ceramide) Used to define human blood groups and types due to antigens
   • Sphingomyelins
     • Head is phosphocholine or phosphoethanolamine Used for neurons
   • Glycosphingolipids
     • Head is connected to a OH (sugar) and no phosphate One is cerebrosides two or more is globosides also called neutral glycolipids due to their pH 7
   • Gangliosides
     • Head is a sialic acid to give a negative charge at pH 7
     • Nervous system

10. Sterol

    • Cholesterol
      • Bile acids
        • Derivatives of cholesterol