ORGANIC CHEMISTRY 354

LIPIDS

CLASSIFICATION

PROPERITIES

CHOLESTEROL

CLASSIFICATION AS A LIPID

SOLUBLE IN CCl₄, CHCl₃, ETHER

INSOLUBLE IN H₂O

USES OF LIPIDS

1. STRUCTURAL COMPONENTS OF CELL MEMBRANES

2. MAINTAIN ORDERLY ARRANGEMENT OF PROTEINS IN CELL MEMBRANES

3. CHIEF STORAGE FORM OF CHEMICAL ENERGY IN ANIMALS

4. MAJOR TRANSPORT SYSTEM FOR NONPOLAR MOLECULES IN AQUEOUS SYSTEMS

5. REGULATORY AGENTS (HORMONES)

TYPES OF LIPIDS

• ESTERS WHICH CAN BE HYDROLYZED

• NONESTERS WHICH CANNOT BE HYDROLYZED

1. WAXES:
   ESTERS OF LONG CHAIN (16-30 CARBONS) ALCOHOLS AND LONG CHAIN (16-30 CARBONS) ACIDS (MIXTURES)
   EXAMPLES:
   • BEESWAX, CERYL MYRISTATE (ANIMAL)
   • CARNAUBA WAX, MYRICYL CEROTATE (PLANT)
   • SPERMACETI WAX, CETYL PALMITATE (ANIMAL)

2. FATS AND OILS:
   TRIESTERS
   • GLYCEROL
   • LONG CHAIN ACIDS (14-22 CARBONS)
   • MIXTURES
   • CALLED GLYCERIDES OR TRIGLYCERIDES
     • FATS - SATURATED ACIDS (ANIMAL)
     • OILS - UNSATURATED ACIDS (PLANT)
   EXAMPLES:
   • A FAT, A SIMPLE TRIGLYCERIDE
   • A FAT, A MIXED TRIGLYCERIDE
   • AN OIL, A MIXED TRIGLYCERIDE
   CHARACTERIZATION OF FATS AND OILS
   1. GAS CHROMATOGRAPHY
      • CONVERT FAT OR OIL TO METHYL ESTER (TRANSESTERIFICATION)

      • ANALYZE BY GC

   2. SAPONIFICATION VALUE (NUMBER) (NOT SAPONIFICATION EQUIVALENT!!!)
      • SAPONIFY FAT OR OIL IN EXCESS POTASSIUM HYDROXIDE

      • TITRATE TO DETERMINE UNREACTED HYDROXIDE

      • SAPONIFICATION VALUE: NUMBER OF MILLIGRAMS OF KOH REQUIRED TO SAPONIFY ONE GRAM OF FAT OR OIL

      • SMALL SAPONIFICATION VALUE = HIGH MOLECULAR WEIGHT

      • LARGE SAPONIFICATION VALUE = LOW MOLECULAR WEIGHT

   3. IODINE VALUE
      • IODINE VALUE: NUMBER OF GRAMS OF IODINE WHICH WILL ADD TO 100 GRAMS OF FAT OR OIL

      • HIGH IODINE VALUE = LARGE DEGREE OF UNSATURATION
   REACTIONS OF FATS AND OILS:

   1. HYDROGENATION

   2. OXIDATION

   3. SAPONIFICATION
      • PRODUCES THE SALT OF A LONG CHAIN ACID

      • CALLED A SOAP
        • SYNTHETIC DETERGENTS

   4. ENZYMATIC DEGRADATION

   5. PHOSPHOLIPIDS AND OTHER COMPLEX LIPIDS
      • LECITHINS
      • CEPHALINS
      • SPHINGOMYLINS
      • GLYCOLIPIDS
      BILAYERS
      CELL MEMBRANES
      GIF OF COMPLEX MEMBRANE

   6. SIMPLE LIPIDS (NONHYDROLYZABLE)
      TERPENES (C₅)_n TERPENOIDS (O, ETC.)
      • FROM STEAM DISTILLATION OF PLANT MATERIALS
      • ESSENTIAL OILS
      • ISOPRENE RULE
      • MONOTERPENES
      • SESQUITERPENES
      • DITERPENES
      • TRITERPENES
      • TETRATERPENES

      • ISOPRENE BIOGENESIS
        • LABELING DATA

      • MONOTERPENES BIOGENESIS
        • LABELING DATA
        • CYCLIC MONOTERPENES
      STEROIDS
      • BIOGENESIS OF LANOSTEROL
      PROSTAGLANDINS

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