LIPID CHEMISTRY

•         LIPIDS ARE ORGANIC COMPOUNDS FOUND IN PLANTS AND ANIMALS.

–        INSOLUBLE IN WATER BUT SOLUBLE IN ORGANIC SOLVENTS, e.g. ETHER, BENZENE, CHLOROFORM, ACETONE

–        ARE ESTERS OF FATTY ACIDS OR SUBSTANCES CAPABLE OF FORMING SUCH ESTERS.

–        UTILIZATION BY THE LIVING ORGANISM

FUNCTIONS OF LIPIDS

•         COMPONENT OF ALL CELLS AND CELL ORGANELLES MEMBRANE

•         MAJOR STORAGE FROM OF CARBON AND ENERGY

•         METABOLIC FUEL AND EMULSIFYING AGENTS

•         PRECURSORS OF OTHER IMPORTANT COMPOUNDS (PROSTAGLANDINS)

•         INSULATING MATERIALS AGAINST ATMOSPHERIC HEAT OR COLD

•         PROTECT ORGANS AGAINST PHYSICAL SHOCK

•         PROTECTIVE COATING OF LIPID, PREVENT EXCESSIVE LOSS OF WATER AND INFECTIONS.

•         TRANSPORT OF FAT SOLUBLE VITAMINS AND OTHER FAT SOLUBLE MATERIALS ACROSS CELL MEMBRANE

•         FURNISHES ENERY TO BIOLOGICAL SYSTEM (9.1 KCAL/G)

FATTY ACIDS

•         MAJOR PHYSIOLOGICAL ROLES

–        BUILDING BLOCKS OF PL. AND GLYCO LIPID OF CELL MEMBRANS

–        FATTY ACID DERIVATIVES ACT AS

•         HORMONES

•         INTERCELLULAR MESSENGER

–        FATTY ACIDS ARE FUEL MOL & STORED AS TRIACYLGLYCEROL

CLASSIFICATION OF
FATTY ACIDS

•         CHAIN LENGTH DEPENDENT

–        SHORT CHAIN FATTY ACID                    [2-4 C]

–        MEDIUM CHAIN FATTY ACID                [6-10]

–        LONG CHAIN FATTYACID                       [12-26 C]

MOST OF FATY ACID IN BLOOD BELONG TO THIS CLASS

•         ESSENTIAL AND NON ESSENTIAL FATTY ACID

–        LINOLEIC ACID      =  W6 SERIES

–        LINOLENIC ACID = W3 SERIES

•         SATURATED AND UNSATURATED

–        MONO-ENOIC

–        DI-ENOIC

–        PLYUNSATURATED FATTY ACID

NOMENCLATURE OF FATTY ACIDS

•         NUMBERING OF FATTY ACIDS FROM–COOH  END ( D NUMBERING)

•         OMEGA (w) NUMBERING OF FATTY ACIDS

•         GREEK LETTERING SYSTEM a, b, g

•         POSITION OF DOUBLE BONDS IS SHOWN FROM w OR D

CLASSIFICATION OF LIPIDS

1. SIMPLE LIPIDS
2. COMPLEX LIPIDS
3. PRECURSORS LIPIDS
4. STEROIDS

SIMPLE LIPIDS:

ALCOHOL + FATTY ACID

a. FATTY ACID –  GLYCEROL

b. WAXES  –  HIGH MOL WT  ALCOHOL + FATTY ACID

2.   COMPLEX LIPIDS: ALCOHOL+F.A+OTHER GROUPS

I.          PHOSPHOLIPIDS

a. GLYCEROPHOSPHOLIPDS: (ALCOHOL  IS GLYCEROL)

•         PHOSPHATIDIC ACID

•         PHOSPHATIDYL GLYCEROL

•         PHOSPHATIDYL CHOLINE

•         PHOSPHATIDYL ETHANOLAMINE

•         PHOSPHATIDYL INOSITOL

•         PHOSPHATIDYL SERINE OR THREONIN

•         LYSOPHOSPHOLIPIDS

•         PLASMALOGENS. (ETHER LINKAGE)

b.   SPHINGO PHOSPHO LIPID – SPHINGOMYLIN

II.  GANGLIOSIDE

CERAMIDE – GLc – Gal – N. Acetylgalactosamine +Gal+Neuraminic acid

GMI GANGLIOSIDE

III. LIPOPOLYSACCHARIDES

–        LIPID + POLYSACCHARIDE

OCCURS IN CELL WALLS OF CERTAIN BACTERIA

IV. LIPOPROTEINS

–        LIPID CORE COVERED BY PROTEIN

OCCURS IN PLASMA

3.   PRECURSORS AND DERIVED LIPIDS

–        FATTY ACIDS

–        GLYCEROL

–        STEROIDS

–        ALCOHOLS

–        FATTY ALDEHYDES

–        KETONE BODIES

–        HYDROCARBONS

–        LIPID SOLUBLE VITAMINS.  VIT A, D, E & K

–        HORMONES OF STEROIDS IN NATURE

4.   STEROID/STEROLS

–        CHOLESTEROL

FUNCTIONS OF CHOELSTEROL

•         CELL MEMBRANES

•         BIL ACID

•         VITAMINE D

•         REGULATION OF GENE

•         STERIOD HORMONES

FUNCTIONS OF PROSTAGLANDIN

•         SMOOTH MUSCLES CONTRACTION (PGE2&PGF2a)

•         LOWER BLOOD PRESSURE

•         REGULATE MENSTRUATION AND FERTILITY

•         INDUCE LABOUR (PGE2 & PGF2a)

•         CONTROL INFLAMMATION

•         RELIEVE ASTHMA AND NASAL CONGESTION (PGE2 & PGI2)

•         INDUCE BLOOD CLOTTING TX A2

•         PREVENT BLOOD CLOTTING (PGI2)

•         PREVENT CONCEPTION

CEREBROSIDES

•         KERASIN

–        FATTY ACID IS LIGNOCERIC ACID

•         CEREBRON

–        FATTY ACID IS HYDROXYLIGNOCERIC ACID

•         NERVON

–        FATTY ACID IS UNSATURATED HOMOLOUG LIGNOCERIC ACID

•         OXYNERVON

–        FATTY ACID IS HYDROXY DERIVATIVES OF NERVONIC ACID