Download Lecture 1. Introduction to Biochemistry

In the name of Gad
‫عناوین مطالب‬
‫‪-1‬اهمیت لیپیدها‬
‫‪ -2‬طبقه بندی لیپیدها‬
‫‪-3‬اسیدهای چرب‬
‫‪ -4‬اسیدهای چرب غیر اشباع‬
‫‪-5‬اسیدهای چرب ترانس و سیس‬
‫‪-6‬انواع اسیدهای چرب‬
‫‪-7‬خواص اسیدهای چرب‬
‫‪-8‬الکلها‬
‫‪-9‬تری آسیل گلیسرولها‬
‫‪ -10‬فسفو آسیل گلیسرول‬
‫‪ -11‬کاردیو لیپین وپالسمالوژن‬
‫‪-12‬فسفولیپازها‬
‫‪-13‬ترپنها ‪،‬مومها‬
‫‪-14‬اسفنگولیپیدها‬
‫‪-15‬استروئیدها‬
‫‪ -16‬غشاءها سلولی‬
‫‪ -17‬پروستاگالندین ها‬
‫‪-18‬لیپو پروتئین ها‬
‫‪Lipids‬‬
‫‪‬‬
‫‪‬‬
‫‪‬‬
‫‪‬‬
‫‪‬‬
‫‪‬‬
‫‪‬‬
‫لیپیدها حاللیت کمتری در آب دارند و بیشتر در حاللهای آلی حل مانند اتر‪،‬‬
‫بنزن ‪..‬حل میشوند‪.‬‬
‫لیپیدها مولکولهای دو قطبی (‪ )amphipathic‬هستند‪.‬‬
‫لیپیدها جزئ اصلی غشاهای سلولی محسوب می شوند‪.‬‬
‫لیپیدها مبنع غنی از انرژی محسوب می شوند‪ 1 .‬گرم ‪9Kcal .....‬‬
‫لیپیدها در انتقال ویتامینهای محلول در چربی (‪(Vit ِD, A, E, K‬‬
‫لیپیدها نقش حفاظتی در برابر سرما دارند‪.‬‬
‫لیپیدها در غشائ سلولهای عصبی درکمک به انتقال امواج عصبی نقش‬
‫دارند‪.‬‬
‫چربی‬
‫‪O‬‬
‫‪R'-O-C-R'' + H2O‬‬
‫‪Formation of an ester:‬‬
‫اسید‬
‫الکل‬
‫‪O‬‬
‫"‪R'OH + HO-C-R‬‬
Classification of Lipids:

Lipids are classified into Three great classes:
Those that only contain fatty acids + ROH = (simple lipids);
-Lipids : fatty acids + Glycerol =TG
- Waxes : fatty acids+ Long alcole
 Those that contain fatty acids + ROH+ another Substance
(complex lipids).
- phospholipids
-Glycolipids
-Lipoprotien
-Sphingolipids
 Steroids

Fatty Acids
Fatty acids = carboxyl group + a long hydrocarbon chain
HO
C
O
C
H2
H2
C
C
H2
H2
C
C
H
H2
C
C
H2
H2
C
C
H2
H2
C
C
H2
H2
C
C
H2
H2
C
CH3
OH
OH
O
O
16:0 =Palmitic Acid=Hexadecanoic acid
18:1 =Oleic acid=9-Octadecenoic acid
Saturated fatty acids are single bonds in all carbon-carbon bonds;
Unstaurated fatty acids contain one or more double bonds in hydrocarbon
chains;
Fatty acids can be named in three ways. See above figure and table 6.1
9
- Number of carbon +Enoic ‫انوئیک‬
-Number of carbon + Anoic ‫آنوئیک‬
18:1
‫ اسید اولئیک‬ω9
Classification of FA:


Saturated chains pack tightly and form more rigid,
organized aggregates (i.e., membranes);
Unsaturated chains bend and pack in a less ordered way,
with greater potential for motion.
Saturated FA
Carboxyl
group
Hyrocarbon
group
Unsaturated FA
Trans & Cis form of USFA
trans form of oleic acid
w3
W9,
w9
w6
w6
cis form of oleic acid
‫غشائ سلولهای شبکیه چشم‬
Common Fatty Acids
Saturated
fatty acids:
Unsaturated
fatty acids:
Octadecadienoic acid
Octadecatrienoic acid
Eicosatetraenoic acid
‫‪Structural Consequences of Unsaturation‬‬
‫اسید شولمگریک اسید چرب حلقوی است‪.‬‬
‫اسید فیتانیک اسید چرب شاخه دار است ‪.‬‬
‫اسید پروستانوئیک‬
‫‪Other Fatty Acids:‬‬
‫‪Cyclic fatty acid‬‬
‫آسید آراشیدیک‬
Properties of Fatty Acids:
Melting Point
-SFA number of carbon ..... MP
-USFA number of double bound …. MP


Saponification (mg KOH ……1gr FAT)
Number of COOH
Number of saponification
‫ کربنه‬4‫اسید بوتیریک‬
‫ کربنه‬24‫اسید لیگنوسریک‬
Properties of Fatty Acids:
Hydrogenation
USFA + H2
SFA
 Binding with O2

O2 + USFA
-Epoxide (‫(اپوکسید‬
-ketoHydroxide )‫(کتو هیدروکسید‬
-En –Diol)‫(اندیول‬
-Proxide)‫(پرواکسید‬

Binding With I2
I2 + USFA
(‫ (یا عدد یدی‬Indies of iodine…..(gr of I2 ….100 gr fat)
Formation of an ester:
‫الکل‬
Alcohols :
‫اسید‬
O
R'OH + HO-C-R"
‫چربی‬
O
R'-O-C-R'' + H2O
1-Glycerol
3-Estrols
2-Sphingosine
OH
H2C
OH
H
C
CH
H3N+
CH
OH
HO
Cholesterol
HC
(CH2 )12
sphingosine
CH3
‫حلقه سیکلو پنتانو فنانترن‬
Lecture 15. Lipids
13
Triglycerols (triglycerides)


Triglycerols consist of a glycerol esterified with three fatty acids
If all fatty acid chains are the same, the molecule is called
triacylglycerol (e.g., tristearin)
•TG is most important of
Storage lipids in fat tissue
And non polar.
Phosphoacylglycerols
a polar head group (X): serine,
choline, ethanolamine, glycerol,
or inositol.
polar
"kink" due to
double bond
non-polar
x
Hydrogen
Phosphatidic acid
Ethanolamine
Phosphatidylethanolamine
Choline
Phosphatidylcholine
Serine
Phosphatidylserine
Inositol
Phosphatidylinositol
‫‪Cardiolipin & Plasmalogen‬‬
‫پالسمالوژن=آلدئید چرب‪+‬مونوآسیل گلیسرول‬
‫پیوند وینیل اتر‬
‫کارديولیپین=فسفاتیدات ‪+‬فسفاتیدات‪+‬گلیسرول‬
‫دی فسفاتيدل گليسرول‬
Phospholipases
B
Lecture 15. Lipids
18
Waxes


Waxes are esters of long-chain alcohols with long-chain fatty
acids;
Waxes are water-insoluble due to
the weakly polar nature of the ester group.
‫استر اسید چرب با‬
‫الکلهای با زنجیره بلند هستند‬
Lecture 15. Lipids
19
Terpenes


Terpenes are a class of lipids from two or
more molecules of 2-methyl-1,2butadiene, or isoprene;
Example of a terpene molecule:
CHO
all-trans-retinal

All sterols (including cholesterol) and
steroid hormones are terpene-based
molecules
OH
Sphingolipids:
Sphingolipids are derivatives of
the lipid sphingosine, which has
a long hydrocarbon tail, and a
polar domain that includes an
amino group.
H2C
OH
H
C
CH
H3N+
CH
HC
(CH2 )12
OH
H2C
O
OH
H
C
CH
NH
CH
C
R
ceramide
HC
(CH2 )12
CH3
R-OH
+
sphingosine
CH3
The amino group of sphingosine
can form an amide bond with a
fatty acid carboxyl, to yield a
ceramide.
Ceramides usually include a polar
head group,
Sphingomyelins
OH
H2C
CH3
OH
H
C
H3C
CH
O
H2
C
N+
H2
C
O
CH3
P
O
phosphocholine
NH
H2C
CH
sphingosine
O
C
ceramide
OH
H
C
CH
NH
CH
HC
O
R

O
fatty acid
(CH2 )12
CH3
FA + Spingosine
Ceramide + phosphocholine
Sphingomyelin
C
R
HC
(CH2 )12
CH3
ceramide (‫(سرامید‬
Sphingomyelin)‫(اسفنگومیلین‬
CH2OH
O
OH
H
OH
Sphingoglycolipids
H
H
H
OH
O
H
H2C
OH
O
cerebroside with
-galactose head group
Ceramide + monosaccharide
Ceramide + monosaccharide + sialic acid
Ceramide + monosaccharide +sulfate
H
C
CH
NH
CH
C
R
HC
(CH2 )12
CH3
Cerebrosides)‫(سربروزید‬
Gangliosides(GM) )‫(گانگلیوزید‬
Sulfatides )‫(سولفاتید‬
Hydrogen
Phosphocholine
Ceramide
Sphingomyelin
Glucose
glucosylcerebroside
Oligosaccharide
Gangliosides
Steroid:
Cholesterol, an
important constituent
of cell membranes,
has a rigid ring
system and a short
branched hydrocarbon
tail.
HO
Cholesterol
Cholesterol is largely hydrophobic.
But it has one polar group, a hydroxyl, making it
amphipathic.
Steroid:
Cholesterol
inserts into bilayer membranes with its OH oriented toward the
aqueous phase & its hydrophobic ring system adjacent to fatty acid
chains of phospholipids. The hydroxyl group of cholesterol forms
hydrogen bonds with polar phospholipid head groups.However
interaction with the relatively rigid cholesterol decreases the mobility of
hydrocarbon tails of phospholipids.
Membrane
Phospholipids
Phospholipid
‫‪Example of steroids‬‬
‫اسید کولیک‬
‫اسید کنوداکسی کولیک‬
‫‪Prostaglandins:‬‬
‫‪:TX‬‬
‫انقباض عظله صاف رگها‬
‫تجمع پالکتی‬
‫‪Prostaglandins inhibitors‬‬
‫‪Dexamethasone‬‬
‫‪indomethacin‬‬
‫‪ibuprofen‬‬
‫ تجمع پالکتی را افزایش می دهند‬‫تنظیم عبور یونها از غشائ‬‫التهاب‬‫تنظیم متابولیسم کلسیم وعضله‬‫‪-‬ترشح موسین از معده‬
Lipid transport in the circulation
Lipids are insoluble in plasma. In order to be transported they are combined
with specific proteins to form lipoproteins:
Proteins (apoproteins)
HO
Non polar lipids in core
(TAG and cholesterol esters)
O
R
O
O
HO
Cholesterol
R
R
HO
Apoproteins are only weakly associated with a particular lipoprotein and are
easily transferred to another lipoprotein of a different class. Apoproteins have
various functions including:
• Structural role
• Binding sites for receptors
• Activators or co-enzymes for enzymes involved with lipid metabolism
Lipoproteins
HDL
LDL & VLDL
Chylomicrons




Assembled in intestinal mucosal cells.
They enter the lymphatic system and enter the blood
via the thoracic duct.
They contain mostly TAG.
Nascent chylomicrons contain apoprotein B48 but pick
up others apoproteins from high density lipoproteins
(HDL) once they enter the circulation.
Apoprotein
phospholipid
Cholesterol ester
Cholesterol
TAG (86%)
Function is to transport dietary TAG to the adipose tissues where it can
be stored as fat or to muscles where the constituent fatty acids can be
used for energy.
The five classes of lipoprotein
(all contain characteristic amounts TAG, cholesterol,
cholesterol esters, phospholipids and apoproteins)
Increasing density
Class
Diameter
(nm)
Source and function
Major apoliproteins
Chylomicrons
(CM)
500
Intestine. Transport of
dietary TAG
A, B48, C(I,II,III) E
Very low density
lipoproteins
(VLDL)
43
Liver. Transport of
B100, C(I,II,III) , E
Low density
lipoproteins
(LDL)
22
Formed in circulation by
partial breakdown of IDL.
Delivers cholesterol to
peripheral tissues
B100
High density
lipoproteins
(HDL)
8
Liver. Removes “used”
cholesterol from tissues
and takes it to liver.
Donates apolipoproteins
to CM and VLDL
A, C(I,II,III), D, E
endogenously
synthesised TAG