struktur Lipida

LIPIDA

Lipids a broad group of Lipids a broad group of compounds that are compounds that are generally soluble inorganic generally soluble inorganic solvents, but only sparingly solvents, but only sparingly soluble in watersoluble in waterC , H, O -- but less OC , H, O -- but less O22 than than carbscarbs

Triglycerides = fats/oilsTriglycerides = fats/oilsCholesterol: technically a Cholesterol: technically a complex “lipid”complex “lipid”

ROLES OF FATROLES OF FAT

Provides concentrated source of Provides concentrated source of energy at 9 calories / gram; reserve energy at 9 calories / gram; reserve of energy in the bodyof energy in the body

Carries essential fatty acids, fat-Carries essential fatty acids, fat-soluble vitaminssoluble vitamins

Enhances palatibility/texture, flavor, Enhances palatibility/texture, flavor, satietysatiety

Cushions organs, insulationCushions organs, insulation Components of cell membranesComponents of cell membranes

LIPIDALIPIDA

►Asam lemak Jenuh C4-C8 = berupa cairan; ►>C8 = berupa padatan►Adanya ikatan rangkap menurunkan titik

cair►Konfigurasi struktur asam lemak jenuh

sangat berbeda sekali dengan asam lemak tidak jenuh

►Adanya ikatan rangkap menyebabkan adanya isomer geometrik (cis dan trans)

►Ikatan rangkap bentuk cis kurang stabil dibanding trans

ROLE OF LIPIDS IN FOOD

►Enhance Flavor Enhance Flavor ►Satiety Satiety ►Texture Texture

Solid to Liquid Solid to Liquid Enhance Tenderness of Pie Crusts Enhance Tenderness of Pie Crusts Flakiness : croissantFlakiness : croissant

►Carry fat-soluble vitamins Carry fat-soluble vitamins ►Can be visible or hidden Can be visible or hidden

Lipids classificationLipids classificationMajor ClassMajor Class SubclassSubclass DescriptionDescription

Simple lipidsSimple lipids Acyl glycerolsAcyl glycerols Glycerol + fatty AcidsGlycerol + fatty AcidsWaxesWaxes Long chain alcohol + long chain FALong chain alcohol + long chain FA

CompoundCompound PAGPAG Glycerol + FA +phosphates + other Glycerol + FA +phosphates + other lipidslipids group N-containinggroup N-containing

SphingolipidsSphingolipids Sphingosine + FA + phosphat + Sphingosine + FA + phosphat + CholineCholine

CerebrocidesCerebrocides Sphingosine + FA + simple sugarSphingosine + FA + simple sugarGangliosidesGangliosides Sphingosine + FA + complex Sphingosine + FA + complex

carbohydate carbohydate moiety moiety

DerivedDerived Materials thatMaterials that carotenoids, steroids,carotenoids, steroids,lipidslipids meet lipid def.meet lipid def. Fat soluble vitaminsFat soluble vitamins

(other than two(other than twoclass)class)

Neutral lipidsNeutral lipids

GlyceridesGlycerides::

Ester of glycerol - Ester of glycerol - mono glycerides, mono glycerides, diglycerides and diglycerides and triglyceridestriglycerides

WaxesWaxes : :simple esters simple esters

of long chain of long chain alcoholsalcohols

H3C (CH2)14 C

O

O CH2 (CH2)28-CH3

long chain alcohol

fatty acid

CH2OH

CH2OH

OHH OH

OH

OH

glycerol is a prochiral molecule

O

OH

OH

R

O

O

OH

O

R

O

R

O

O

O

R

O

R

O

OR

O

MONOGLYCERIDE DIGLYCERIDE TRIGLYCERIDE

Function: storage of energy in compact form and cushioning

GLYCERIDE

H H--C—OH

H--C—OH +

H--C—OH

H

O

HO-C-R

O

HO-C-R

O

HO-C-R

H O

H--C--O--C—H + H2O

O

H--C--O--C—H + H2O

O

H--C--O--C—H + H2O

H

(Ester bond)

TRIGLISERIDA

Glyserol + 3 FA’s Triglyseride + 3 H2O

esterificationesterification

hydrolysishydrolysis

H

H--C--OH

H--C—OH +

H--C--OH

H

Fatty AcidFatty AcidFatty Acid

H O

H--C--O--C—fatty acid

O

H--C--O--C—fatty acid

O

H--C--O--C—fatty acid

H

TRIGLISERIDA

Triasilgliserol/Trigliserida (Lipida netral)

Triglyceride = glycerol with 3 fatty acid chains

(CH2)14H3C CH2-OH cetyl alcohol

(CH2)24H3C CH2-OH hexacosanol

(CH2)28H3C CH2-OH triacontanol (myricyl alcohol)

WaxesWaxes

Long chain alcohol + long chain FAExamples of long chain monohydric alcohols found in waxes

Fatty acidsFatty acids► Carboxylic acid derivatives of long chain Carboxylic acid derivatives of long chain

hydrocarbonshydrocarbons

General structure:General structure:

CH3 – (CH2)n – COOH

n is always even

Chain of C with -COOH endH- along -C- chain

NomenclatureStearate – stearic acid – C18:0 – n-octadecanoic acid

-Long chain FA -Long chain FA >> 12 12 CarbonsCarbons-Medium chain FA 6 - 10 -Medium chain FA 6 - 10 CarbonsCarbons-Short chain FA < 6 -Short chain FA < 6 CarbonCarbon

Classification of Fatty Acids Classification of Fatty Acids C chainC chain

The chain length has an effect The chain length has an effect on how liquid a fat/oil is at on how liquid a fat/oil is at room temperatureroom temperature

Common fatty acidsn = 4 n = 4 butyric acid (butanoic acid)butyric acid (butanoic acid)n = 6 n = 6 caproic acid (hexanoic acid)caproic acid (hexanoic acid)n = 8 n = 8 caprylic acid (octanoic acid)caprylic acid (octanoic acid)n = 10 capric acid (decanoic acid)n = 10 capric acid (decanoic acid)n = 12 lauric acid (n-dodecanoic acid; Cn = 12 lauric acid (n-dodecanoic acid; C12:012:0))n = 14 myristic acid (n-tetradecanoic acid; n = 14 myristic acid (n-tetradecanoic acid;

CC14:014:0))n = 16 palmitic acid (n-hexadecanoic acid; Cn = 16 palmitic acid (n-hexadecanoic acid; C16:016:0))n = 18 stearic acid (n-octadecanoic acid; Cn = 18 stearic acid (n-octadecanoic acid; C18:018:0))n = 20 arachidic (eicosanoic acid; Cn = 20 arachidic (eicosanoic acid; C20:020:0))n = 22 behenic acidn = 22 behenic acidn = 24 lignoceric acidn = 24 lignoceric acidn = 26 cerotic acidn = 26 cerotic acid

Fatty acidsFatty acids

Fatty acids can be classified either as:Fatty acids can be classified either as:

according to chain length:according to chain length:

saturated or unsaturatedsaturated or unsaturated

essential fatty acids vs those that essential fatty acids vs those that

can be biosynthesized in the body:can be biosynthesized in the body:►linoleic and linolenic are two linoleic and linolenic are two examples of essential fatty examples of essential fatty acidacid

Classification of Fatty Acids Classification of Fatty Acids double bonddouble bond

►Saturated fatty acidsSaturated fatty acids No double bondsNo double bonds solid at room tempsolid at room temp

►Monounsaturated FAMonounsaturated FA One double bondOne double bond liquid at room templiquid at room temp

►Polyunsaturated FA (PUFA)Polyunsaturated FA (PUFA) >= 2 double bonds>= 2 double bonds liquid at room templiquid at room temp Omega 3 FA from fishOmega 3 FA from fish

The building block of lipids are The building block of lipids are fatty acidsfatty acids

Omega endOmega end alpha endalpha end Note that all carbons have two hydrogens – this is a fully saturated Note that all carbons have two hydrogens – this is a fully saturated

fatty acid.fatty acid.

H H H H H H H H H H H H H H H H H O

H-C--C--C--C--C--C--C--C--C--C--C--C--C--C--C--C--C-C-OH

H H H H H H H H H H H H H H H H H

Unsaturated fatty acidsUnsaturated fatty acids

►Monoenoic acid (monounsaturated)Monoenoic acid (monounsaturated)

H3C

HOOC

Double bond is alwayscis in natural fatty acids.This lowers the meltingpoint due to “kink” inthe chain

Monounsaturated Fatty Acid Monounsaturated Fatty Acid (MUFA) Structure(MUFA) Structure

H H H H H H H H H H H H H H H OH-C--C--C--C--C--C--C--C--C=C--C--C--C--C--C--C--C--C-OH H H H H H H H H H H H H H H H H H

Omega Omega endend

Alpha Alpha endend

When two Hs are lost from two adjacent Carbons, a double When two Hs are lost from two adjacent Carbons, a double bond is formed. This is an unsaturated FAbond is formed. This is an unsaturated FA

Polyunsaturated Fatty Acid (PUFA) Polyunsaturated Fatty Acid (PUFA) StructureStructure

H H H H H H H H H H H H OH-C--C—C=C--C--C=C--C--C=C--C--C--C--C--C--C--C--C-OH H H H H H H H H H H H H H H H H

omega endomega end alpha end alpha endTwo or more double bonds results in Two or more double bonds results in a polyunsaturated fatty acid.a polyunsaturated fatty acid.

Unsaturated fatty acidsUnsaturated fatty acids

►Monoenoic acids (one double bond):Monoenoic acids (one double bond):►16:1, 9 16:1, 9 7: palmitoleic acid (7: palmitoleic acid (ciscis-9-hexadecenoic -9-hexadecenoic

acidacid

►18:1, 9 18:1, 9 9: oleic acid (9: oleic acid (ciscis-9-octadecenoic acid)-9-octadecenoic acid)

►18:1, 9 18:1, 9 9: elaidic acid (9: elaidic acid (transtrans-9-octadecenoic -9-octadecenoic

acid)acid)

►22:1, 13 22:1, 13 9: erucic acid (9: erucic acid (ciscis--13-docosenoic acid)13-docosenoic acid)

►24:1, 15 24:1, 15 9: nervonic acid (9: nervonic acid (ciscis-15-tetracosenoic -15-tetracosenoic

acid)acid)

Unsaturated fatty acidsUnsaturated fatty acids

►Dienoic acid: linoleic acidDienoic acid: linoleic acid

(CH2)4CH3 CH=CH CH2 CH=CH (CH2)7 COOH

cis

linoleic acid

Unsaturated fatty acidsUnsaturated fatty acids

►Polyenoic acid (polyunsaturated)Polyenoic acid (polyunsaturated)

COOH

CH3

Unsaturated fatty acidsUnsaturated fatty acids

►Trienoic acids (3 double bonds)Trienoic acids (3 double bonds)►18:3;6,9,12 18:3;6,9,12 6 : 6 : -linolenic acid (all -linolenic acid (all ciscis--

6,9,12-octadecatrienoic acid)6,9,12-octadecatrienoic acid)►18:3; 9,12,15 18:3; 9,12,15 3 : 3 : -linolenic acid (all--linolenic acid (all-ciscis--

9,12,15-octadecatrienoic acid)9,12,15-octadecatrienoic acid)

►Tetraenoic acids (4 double bondsTetraenoic acids (4 double bonds))►20:4; 5,8,11,14 20:4; 5,8,11,14 6: arachidonic acid (all-6: arachidonic acid (all-ciscis--

5,8,11,14-eicosatetraenoic acid)5,8,11,14-eicosatetraenoic acid)

Unsaturated fatty acidsUnsaturated fatty acids

►Pentaenoic acid (5 double Pentaenoic acid (5 double bonds)bonds)

►20:5; 5,8,11,14,17 20:5; 5,8,11,14,17 3: timnodonic 3: timnodonic acid or EPA (all-acid or EPA (all-ciscis-5,8,11,14,17--5,8,11,14,17-eicosapentaenoic acid)*eicosapentaenoic acid)*

►Hexaenoic acid (6 double bonds)Hexaenoic acid (6 double bonds)►22:6; 4,7,10,13,16,19 22:6; 4,7,10,13,16,19 3: cervonic 3: cervonic

acid or DHA (all-cis-4,7,10,13,16,19-acid or DHA (all-cis-4,7,10,13,16,19-docosahexaenoic acid)*docosahexaenoic acid)*

Both FAs are found in cold water fish oils

RCORCO22HH ++ NaHCONaHCO33 RCORCO22(–)(–) Na Na(+)(+)   +   CO   +   CO22   +     +  

HH22OO

RCORCO22HH ++ (CH(CH33))33N:N: RCORCO22(–)(–) (CH (CH33))33NHNH(+)(+)

RCORCO22HH ++ AgOHAgOH RCORCO22δ(–)δ(–) Ag Agδ(+)δ(+)   +   H   +   H22OO

Special reactions of fatty acids

• Carboxylic acids react with bases to form ionic salts, • In the case of alkali metal hydroxides and simple

amines (or ammonia) the resulting salts have pronounced ionic character and are usually soluble in water.

• Heavy metals such as silver, mercury and lead form salts having more covalent character and the water solubility is reduced, especially for acids composed of four or more carbon atoms.

PHOSPHOLIPID

PhospholipidPhospholipid

MONOLAYER

BILAYER

Gambar. Liposom

OH

NH2

OH

NH2

OH

HO R long chain hydrocarbon

attach fatty acid here

attach polar head group here

sphingosine

Based on sphingosine instead of glycerol

SphingolipidsSphingolipids

SPHINGOLIPID

NH

O

HO

R

PO

O-

O

N(CH3)+

R'

O

usually palmitic acid

phosphatidyl choline (also can be ethanolamine)

SphingomyelinSphingomyelin

NH

O

HO R

R'

O

SUGAR polar head is a sugar

beta linkage

GlycolipidsGlycolipids

GLYCOLIPIDS

LipoproteinsLipoproteins

► particles found in plasma that transport particles found in plasma that transport lipids including cholesterollipids including cholesterol

► lipoprotein classeslipoprotein classes►chylomicrons: take lipids from small chylomicrons: take lipids from small

intestine through lymph cellsintestine through lymph cells►very low density lipoproteins (VLDL)very low density lipoproteins (VLDL)►intermediate density lipoproteins (IDL)intermediate density lipoproteins (IDL)►low density lipoproteins (LDL)low density lipoproteins (LDL)►high density lipoproteins (HDL)high density lipoproteins (HDL)

A multi-ringed structureA multi-ringed structureDo not have a glycerol backboneDo not have a glycerol backboneWaxy substanceWaxy substanceDo not readily dissolve in waterDo not readily dissolve in waterCholesterol is a sterol Cholesterol is a sterol

SterolsSterols

CholesterolCholesterol• • Sterol family memberSterol family member• • Found in large amounts in the plasma Found in large amounts in the plasma membranemembrane• • Fill spaces between neighboring phospholipid Fill spaces between neighboring phospholipid moleculesmolecules• • Tend to make bilayers more rigid and less Tend to make bilayers more rigid and less permeablepermeable

HO

HH

H

O

HH

H

R

O

usually palmitate

Cholesterol and cholesterol Cholesterol and cholesterol estersesters

The hydroxyl at C-3 is hydrophilic; the rest of themolecule is hydrophobic; also 8 centers of asymmetry

Functions of cholesterolFunctions of cholesterol

►serves as a component of serves as a component of membranes of cells (increases or membranes of cells (increases or moderates membrane fluidity)moderates membrane fluidity)

►precursor to steroid hormones and precursor to steroid hormones and bile acidsbile acids

►storage and transport –cholesterol storage and transport –cholesterol estersesters

Less common fatty acidsLess common fatty acids

► iso – isobutyric acid, iso – isobutyric acid, Branched Branched

► odd carbon fatty acid – odd carbon fatty acid – propionic acidpropionic acid

► hidroxy fatty acids – hidroxy fatty acids – ricinoleic acid, ricinoleic acid, dihydroxystearic acid, dihydroxystearic acid, cerebronic acidcerebronic acid

► cyclic fatty acids – cyclic fatty acids – hydnocarpic, hydnocarpic, chaulmoogric acidchaulmoogric acid

H3CR

CH3

(CH2)12-CO2H (CH2)10-CO2H

chaulmoogric acid hydnocarpic acid

H3CR

CH3

Stereospecific numberingStereospecific numbering

► C-1 and C-3 of the glycerol molecule C-1 and C-3 of the glycerol molecule become sn1 and sn3 respectivelybecome sn1 and sn3 respectively

► carbon 2 of triglycerides is frequently carbon 2 of triglycerides is frequently asymmetric since C-1 and C-3 may be asymmetric since C-1 and C-3 may be substituted with different acyl groupssubstituted with different acyl groups

► by convention: the hydroxyl group at C-by convention: the hydroxyl group at C-2 to the left and use the designation of 2 to the left and use the designation of sn2 for that particular substituentsn2 for that particular substituent

EmulsifierEmulsifier

► Hydrophilic end Hydrophilic end (attracts water)(attracts water)

► Hydrophobic Hydrophobic end (attracts end (attracts lipid)lipid)

EmulsificationEmulsification Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

GLYCOLIPIDSGLYCOLIPIDS► CerebrosidesCerebrosides

► One sugar moleculeOne sugar molecule Galactocerebroside – in neuronal membranesGalactocerebroside – in neuronal membranes Glucocerebrosides – elsewhere in the bodyGlucocerebrosides – elsewhere in the body

► Sulfatides or sulfogalactocerebrosidesSulfatides or sulfogalactocerebrosides► A sulfuric acid ester of galactocerebrosideA sulfuric acid ester of galactocerebroside

► Globosides: ceramide Globosides: ceramide oligosaccharidesoligosaccharides

► LactosylceramideLactosylceramide► 2 sugars ( eg. lactose)2 sugars ( eg. lactose)

► GangliosidesGangliosides► Have a more complex oligosaccharide attachedHave a more complex oligosaccharide attached► Biological functions: cell-cell recognition; receptors for Biological functions: cell-cell recognition; receptors for

hormoneshormones

Lipoprotein classesLipoprotein classes

• Chylomicrons B48 85%

•VLDL B100/E 20% 55%

• IDL B100/E 35% 25%

• LDL B100 60% 5%

•HDL AI/II/E 20% 5%

protein choles.triglycerides

LDL is not measured but calculated:

LDL-C = total cholesterol - (HDL-C + TG/5)

(Triglycerides must be <4.5 mmol/L or < 400 mg/dL)

LDL moleculeLDL molecule

STEROID NUMBERING STEROID NUMBERING SYSTEMSYSTEM

A B

C D1

2

3

45

6

7

89

10

1112

13

14 15

16

1718

19

TestosteroneTestosterone(a steroid hormone)(a steroid hormone)

Vitamin D3Vitamin D3(cholecalciferol) (cholecalciferol)