Metabolisme Energi dan Zat Gizi Makro Pertemuan 6.

LIPID METABOLISM
Hendra Wijaya
Esa Unggul University
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7/22/2017
Metabolisme Lipida
INDEKS
CHARACTERISTICS OF LIPID
DIGESTION AND ABSORPTION OF LIPID
TRANSPORT OF LIPID
BETA-OXIDATION OF LIPID
SYNTHESIS OF LIPID
CHARACTERISTIC
OF
LIPID
Hendra Wijaya
Esa Unggul University
3
7/22/2017
Metabolisme Lipida
ROLE OF LIPIDS IN FOOD
Enhance Flavor
Satiety
Texture
Solid to Liquid
Enhance Tenderness
Carry fat-soluble vitamins
Can be visible or hidden
ROLE OF LIPIDS IN THE BODY
Energy (9 kcal/gram)
Energy to make muscles contract,
including heart - supplied mostly from fat
Insulate body against temperature extremes
Protect the body’s vital organs from shock
Form the major material of cell membranes
Nerve transmission
Contain or transport fat-soluble vitamins
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TYPES OF
LIPIDS
IN THE BODY
Fatty Acids
Triglycerides
Sterols
Phospholipids
Metabolisme Lipida
CHARACTERISTICS OF FATTY ACIDS
Rarely exist alone - are part of triglycerides or phospholipids
Structure :
Chain Length - Short (2-4 C), Medium (6-10 C), Long (>12 C)
Saturation = Presence or Absence of Double Bonds
Saturated Fatty Acids
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Unsaturated Fatty Acids
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Metabolisme Lipida
CHARACTERISTICS OF FATTY ACIDS
Trans- and Cis-Fatty Acids
Trans- result when PUFA’s are hydrogenated.
In hydrogenation the double bond is broken and is saturated with H atoms
Has same health effects as saturated fatty acids
Cis- how most fats occur in nature. The hydrogens next to the double
bonds are on the same side of the carbon chain.
MAY NOT BE AS CHOLESTEROL RAISING AS TRANS-FATTY ACIDS
3/22/2007
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Metabolisme Lipida
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Metabolisme Lipida
TRANS-FATS
Dietary trans fats raise the level of low-density
lipoproteins (LDL or "bad cholesterol"). Trans
fats also reduce high-density lipoproteins (HDL
or "good cholesterol"), and raise levels of
triglycerides in the blood.

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increasing the risk of coronary heart disease.
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Metabolisme Lipida
THE TOP 10 TRANS-FAT FOODS
Data: U.S. Food & Drug Administration (2011)
salad dressing
mayonnaise
fried potato
margarine
doughnut
crispy fried potato
cake
chocolate bar
Trans fatty acids:
not only increase LDL
level, but also decrease
HDL level
creamy biscuit
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margarine spread
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Metabolisme Lipida
Essential Fatty Acids
Human body cannot make a C=C bond before the 10th carbon in a fatty
acid. Thus, essential fatty acids must come from food sources
18:2; 9,12  asam linoleat;
18:3; 9, 12, 15  asam linolenat
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Metabolisme Lipida
Asam linoleat dan linolenat tergolong sebagai asam lemak esensial (tidak dapat disintesis
oleh tubuh), sehingga harus selalu disuplai dari makanan.
Gejala klinis yang menandai defisiensi asam lemak esensial antara lain, kulit kasar dan
kering, terhambatnya pertumbuhan pada bayi dan anak-anak, meningkatnya kemudahan
terserang infeksi dan luka yang tidak cepat sembuh (Jeppesen et al, 1998).
Tahap
Kehidupan
Bayi
Bayi
Anak-anak
Anak-anak
Anak-anak
Remaja
Dewasa
Dewasa
Ibu hamil
Ibu menyusui
Umur (tahun)
0-6 bl
7-12 bl
1-3 th
4-8 th
9-13 th
14-18 th
19-50 th
> 51
Semua umur
Semua umur
Sumber AL
omega-6
ASI
ASI
LA
LA
LA
LA
LA
LA
LA
LA
Laki-laki
(g/hari)
4,4
4,6
7,0
10,0
12,0
16,0
17,0
14,0
-
Tahap
Kehidupan
Bayi
Bayi
LA = asam linoleat
ALA = asam alfa-linolenat,
EPA = asam eikosapentaenoat;
DHA = asam dokosaheksaenoat.
Sumber: Institute of Medicine (2002).
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Wanita
(g/hari)
4,4
4,6
7,0
10,0
10,0
11,0
12,0
11,0
13,0
13,0
Umur (tahun)
0-6 bl
7-12 bl
Anak-anak
Anak-anak
Anak-anak
Remaja
Dewasa
Ibu hamil
Ibu menyusui
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1-3 th
4-8 th
9-13 th
14-18 th
> 19 th
Semua umur
Semua umur
Kecukupan konsumsi asam
lemak omega-6 dan omega-3
yang dianjurkan
Sumber AL
omega-3
ALA, EPA,
DHA
ALA, EPA,
DHA
ALA
ALA
ALA
ALA
ALA
ALA
ALA
Laki-laki
(g/hari)
Wanita
(g/hari)
0,5
0,5
0,5
0,7
0,9
1,2
1,6
1,6
-
0,5
0,7
0,9
1,0
1,1
1,1
1,4
1,3
Metabolisme Lipida
TRIGLYCERIDES
• Glycerol Molecule + 3 FA Molecules
• Storage form of fatty acids in the body
• Most common fat in foods - 95%
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Metabolisme Lipida
PHOSPHOLIPIDS
 These compounds are





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similar to triglycerides,
but have choline
(or another compound)
and a phosphoruscontaining acid
in place of one of the
fatty acids
Have a hydrophobic and
hydrophilic end
They are important
constituents of cell
membranes
Help form micelles which are
emulsifiers
Lecithin is a well known
phospholipid
These compounds are not
essential
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Metabolisme Lipida
STEROID
Most cholesterol is made by the body
 Very little cholesterol in foods except:
Shellfish, Eggs

Brains, Liver,
Other lipid: Eicosonoid