struktur lipida
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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)
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