Lipids
Duanqing Pei,Ph.D,
裴 端 卿
Tsinghua University
Cell phone,136-8301-7108
peixx003@umn.edu
fuxinmiao00@mails.tsinghua.edu.cn
Introduction
? A diverse group of water-insoluble
(hydrophobic) compounds
? three types of lipids—storage or
structural lipids,―bioactive‖ lipids
Lipid basics,Fatty acids
? Fats and oils—made of fatty acids
? Fatty acids—long chain
hydrocarbon derivatives,Low
oxidative state,excellent source of
energy
Fatty acids
? Carboxylic acids with hydrocarbon
chains of 4 to 36 carbons long (C4 to
C36)
? Both saturated and unsaturated (double
bonded)
? Unbranched,branched (methyl group),
or three carbon rings
Naming Convention
? 12:0
? 16:1(D9)
? 20:4(D5,8,11,14)
Two representation of
the fully saturated acid,
stearic acid—18:0
The zigzag form and
space-filling model
Carbon #1
Carbon #18
Unsaturated bond
(a cis double bond-
rigid bend)
Oleic Acid (18:1D9)
Fully saturated fatty acids in the
extended form pack into nearly
crystalline arrays,stabilized by many
hydrophobic interactions
h
y
d
r
o
p
h
o
b
i
c
h
y
d
r
o
p
h
o
b
i
c
Less stable
aggregates
Physical Properties of Fatty Acids
1) Determined by length and degree of
unsaturation of hydrocarbon chain.
2) Melting points
3) Solubility in water and benzene
Structural Basis of Melting points for fatty acids
In vertebrates,free fatty acids
(unesterified fatty acids having a free
carboxylate group) circulate in the
blood bound noncovalently to a
protein carrier,serum albumin.
However,most of the fatty acids are
derivatives of esters or amides—thus,
lack the charged carboxylate group—
less soluble,
Biologically speaking…,.
Triacylglycerols
—fatty acid ester of glycerol
also called triglycerides,fats or neutral fats
--simple triacylglycerols—all three fatty acids are
the same,e.g.,16:0-tristearin; 18:0-tripalmitin,18:1-
triolein
--mixed triacylglycerol-two or more fatty acids
-- triacylglycerols are nonpolar,hydrophobic and
insoluble (oil/water—never mix),
1-stearoyl,2-linoleoyl,3-
palmitoyl glycerol
A mixed triglyceride
C2 is a chiral center
Triacylglycerols—stored energy and insulation
Fat stores in cells—adipocytes and plant seeds
Fat droplets
Fat droplets
in plant seeds
(Arabidopsis)
Major component,lipid
Controls density and buoyancy when diving deep into the ocean
Sperm Whales
Fatty acid composition of
three food fats
Food fats may be spoiled and
become rancid—oxidative
cleavage of double bonds into
aldehydes and carboxylic
acids—odor and volatile
Wax,energy source
and water repellents
--esters of long-chain (C14-
36)saturated and
unsaturated fatty acids with
long-chain (C16-30) alcohols
Wax—bee was from honeycomb
Function of Waxes in nature:
1) energy source– for
plankton
2) water repellents—bird
feathers,vertebrates’ hair
and skin,plant leaves (shiny
ones such as those of
poison ivy)
3)structural—bee wax
Waxes in industry
1)Sources,Lanolin (lamb
wood),beeswax,carnauba
wax and spermaceti oil
2)Usage,ointments,lotions
and polishes
Structural Lipids in Membranes
1)The biological membranes—a
bilayer of lipids as barriers for
water soluble molecules
2)Three major types,
glycerophospholipds,
sphingolipids,and sterols.
Principal Classes
of Storage and Membrane lipids
L-glycerol 3-phosphate,backbone of phospholipid
Glycerophospholipids
Phosphatidic acid
Unusual phospholipids:
Plasmalogens,ether-linked alkenyl chain instead of ester-
linked fatty acid
PAF,long ether-linked alkyl chain at C-1,C-2 is linked to Acetic
acid—more solubility
Released by basophils to stimulate platelet aggregation and release
of serotonin (vasoconstrictor)
Sphingolipids:
Derived from
sphingosine—a
amino alcohol
(like diacylglycerol)
N-acetylneuraminic acid (sialic acid)
The similarities in shape and in molecular structure
of phosphatidylcholine (a glycerophopholipid) and
spingomyelin (a sphingolipid)
glycerol sphingosine
Palmitic
acid
N-acetylneuraminic
acid (sialic acid)
Determination of blood
type
by glycosphingolipids—
actually the carbohydrate
moieties on sphingolipids N-acetyl-D-galactosamine
D-galactose
Specificity of phopholipases (mostly in lysosomes)
Phosphatidylinositol 4,5 bisphosphate
Ester bonds
Phosphodiester bonds
Pathways for the breakdown of GM1,globoside,sphingomyelin to
ceramide (lysosomal hydrolases)
Any defects in any
of these enzymes
lead to
accumulation of
gangliosides in
cells—diseases
such as Niemann-
Pick diseases
(sphingomyelin
accumulates in
brain,spleen,liver-
mental retardation.
Pathways for the breakdown of GM1,globoside,sphingomyelin to
ceramide (lysosomal hydrolases)
Tay-Sachs
disease—GM2
accumulates in
brain and spleen—
progressive
retardation in
development,
paralysis,blindness
and death by the
age of 3 or 5 yrs
Pathways for the breakdown of GM1,globoside,sphingomyelin to
ceramide (lysosomal hydrolases)
Fabry’s disease,
Gaucher’s disease
Sandhoff’s disease
EM of a brain from a infant with Tay-
Sachs disease—abnormal deposits of
gangliosides in lysosomes
Sterols—structural lipids in membranes of most eukaryotic cells,
Steroid nucleus—four fused rings—3 six carbon,1 five carbon,
Cholesterol_ rings A-
D,At C3,there is a
hydroxyl group (OH)
as the head polar
group,It condenses
with fatty acids to
form a sterol ester for
storage and transport
Bile acids are poplar derivatives of cholesterol that acts like a
detergents in the intestine,emulsifying dietary fats to make them
readily accessible to digestive lipases,
Lipids as signals,cofactors and pigments
1) membrane- 5-10% dry mass of a cell,storage as 80% in
adipocytes.—both passive molecules—less exciting?
2) Third class of lipids are the active lipids; a) secondary
messengers (intracellular),hormones in the blood stream,
b) co-factors /enzymes in the electron-transfer reactions in
chloroplasts and mitochondria,or transfer of sugar moiety
in glycosylation,c) pigment molecules that absorb visible
light—light capturing in vision and photosynthesis,or
natural coloration—pumpkins,carrots,They all come from
membrane or vitamins such as A,D,E and K.
Phosphatidylinositols as
intracellular signals
Also binds to
cytoskeleton proteins
and those involved in
membrane fusion in
exocytosis
When stimulated by hormones,phospholypase A2 releases
arachidonic acid from membrane phospholipids,Arachidonic acid
is the precursor of various bioactive eicosanoids—prostaglandins,
PGE1,thromboxanes A2,and leukotrienes A4,
Arachidonic Acid and Eicosanoid derivatives
Bengt Samuelsson
and Sune
Bergstrom—regulate
cAMP synthesis in
response to
hormones,also SMC
contraction-labor,
blood flow,wake-
sleep cycle,PGE3
cyclooxygenase
NSAID,asprin,
acetaminophen,
ibuprogen
Jane Vane—made
by platelets-promote
blood clots and
reduce blood flow to
clot site
Released from
leukocytes,D4
induces contraction
of muscles lining the
airway to lung,
Overproduction—
asthmatics—target
for antiasthmatic
drug such as
prednisone
Hormones—messages
between tissues
Testosterone—made
in testes
Estradiol—ovaries
and placenta,
Cortisol and
aldosterone—cortex
of adrenal gland—
regulate glucose
metabolism and salt
excretion
Prednisone—
antiinflammatory drug
Vitamins– those are essential to health,but not synthesized by
them,thus,must be provided by food!
We will consider A,D,E,K,
Synthesis of vitamin D
Control calcium metabolism in
kidney,intestine,and bone
Vitamin A1,its precursors and derivatives
Two
molecules
Henrik Dam and Edward A Doisy– discovered that K
deficiency slows down clotting,
K1 undergoes a cycle of oxidation and reduction during the
formation of active prothrombin,Warfarin inhibits this process
Sugars are activated by attaching to isoprenoid alcohol-
dolichols; they are hydrophobic,thus,anchored on membrane to
provide the anchored sugar to the sugar transfer reactions.
Common Procedures in the extraction,
separation,and identification of
cellular lipids
Thank you!
Duanqing Pei,Ph.D,
裴 端 卿
Tsinghua University
Cell phone,136-8301-7108
peixx003@umn.edu
fuxinmiao00@mails.tsinghua.edu.cn
Introduction
? A diverse group of water-insoluble
(hydrophobic) compounds
? three types of lipids—storage or
structural lipids,―bioactive‖ lipids
Lipid basics,Fatty acids
? Fats and oils—made of fatty acids
? Fatty acids—long chain
hydrocarbon derivatives,Low
oxidative state,excellent source of
energy
Fatty acids
? Carboxylic acids with hydrocarbon
chains of 4 to 36 carbons long (C4 to
C36)
? Both saturated and unsaturated (double
bonded)
? Unbranched,branched (methyl group),
or three carbon rings
Naming Convention
? 12:0
? 16:1(D9)
? 20:4(D5,8,11,14)
Two representation of
the fully saturated acid,
stearic acid—18:0
The zigzag form and
space-filling model
Carbon #1
Carbon #18
Unsaturated bond
(a cis double bond-
rigid bend)
Oleic Acid (18:1D9)
Fully saturated fatty acids in the
extended form pack into nearly
crystalline arrays,stabilized by many
hydrophobic interactions
h
y
d
r
o
p
h
o
b
i
c
h
y
d
r
o
p
h
o
b
i
c
Less stable
aggregates
Physical Properties of Fatty Acids
1) Determined by length and degree of
unsaturation of hydrocarbon chain.
2) Melting points
3) Solubility in water and benzene
Structural Basis of Melting points for fatty acids
In vertebrates,free fatty acids
(unesterified fatty acids having a free
carboxylate group) circulate in the
blood bound noncovalently to a
protein carrier,serum albumin.
However,most of the fatty acids are
derivatives of esters or amides—thus,
lack the charged carboxylate group—
less soluble,
Biologically speaking…,.
Triacylglycerols
—fatty acid ester of glycerol
also called triglycerides,fats or neutral fats
--simple triacylglycerols—all three fatty acids are
the same,e.g.,16:0-tristearin; 18:0-tripalmitin,18:1-
triolein
--mixed triacylglycerol-two or more fatty acids
-- triacylglycerols are nonpolar,hydrophobic and
insoluble (oil/water—never mix),
1-stearoyl,2-linoleoyl,3-
palmitoyl glycerol
A mixed triglyceride
C2 is a chiral center
Triacylglycerols—stored energy and insulation
Fat stores in cells—adipocytes and plant seeds
Fat droplets
Fat droplets
in plant seeds
(Arabidopsis)
Major component,lipid
Controls density and buoyancy when diving deep into the ocean
Sperm Whales
Fatty acid composition of
three food fats
Food fats may be spoiled and
become rancid—oxidative
cleavage of double bonds into
aldehydes and carboxylic
acids—odor and volatile
Wax,energy source
and water repellents
--esters of long-chain (C14-
36)saturated and
unsaturated fatty acids with
long-chain (C16-30) alcohols
Wax—bee was from honeycomb
Function of Waxes in nature:
1) energy source– for
plankton
2) water repellents—bird
feathers,vertebrates’ hair
and skin,plant leaves (shiny
ones such as those of
poison ivy)
3)structural—bee wax
Waxes in industry
1)Sources,Lanolin (lamb
wood),beeswax,carnauba
wax and spermaceti oil
2)Usage,ointments,lotions
and polishes
Structural Lipids in Membranes
1)The biological membranes—a
bilayer of lipids as barriers for
water soluble molecules
2)Three major types,
glycerophospholipds,
sphingolipids,and sterols.
Principal Classes
of Storage and Membrane lipids
L-glycerol 3-phosphate,backbone of phospholipid
Glycerophospholipids
Phosphatidic acid
Unusual phospholipids:
Plasmalogens,ether-linked alkenyl chain instead of ester-
linked fatty acid
PAF,long ether-linked alkyl chain at C-1,C-2 is linked to Acetic
acid—more solubility
Released by basophils to stimulate platelet aggregation and release
of serotonin (vasoconstrictor)
Sphingolipids:
Derived from
sphingosine—a
amino alcohol
(like diacylglycerol)
N-acetylneuraminic acid (sialic acid)
The similarities in shape and in molecular structure
of phosphatidylcholine (a glycerophopholipid) and
spingomyelin (a sphingolipid)
glycerol sphingosine
Palmitic
acid
N-acetylneuraminic
acid (sialic acid)
Determination of blood
type
by glycosphingolipids—
actually the carbohydrate
moieties on sphingolipids N-acetyl-D-galactosamine
D-galactose
Specificity of phopholipases (mostly in lysosomes)
Phosphatidylinositol 4,5 bisphosphate
Ester bonds
Phosphodiester bonds
Pathways for the breakdown of GM1,globoside,sphingomyelin to
ceramide (lysosomal hydrolases)
Any defects in any
of these enzymes
lead to
accumulation of
gangliosides in
cells—diseases
such as Niemann-
Pick diseases
(sphingomyelin
accumulates in
brain,spleen,liver-
mental retardation.
Pathways for the breakdown of GM1,globoside,sphingomyelin to
ceramide (lysosomal hydrolases)
Tay-Sachs
disease—GM2
accumulates in
brain and spleen—
progressive
retardation in
development,
paralysis,blindness
and death by the
age of 3 or 5 yrs
Pathways for the breakdown of GM1,globoside,sphingomyelin to
ceramide (lysosomal hydrolases)
Fabry’s disease,
Gaucher’s disease
Sandhoff’s disease
EM of a brain from a infant with Tay-
Sachs disease—abnormal deposits of
gangliosides in lysosomes
Sterols—structural lipids in membranes of most eukaryotic cells,
Steroid nucleus—four fused rings—3 six carbon,1 five carbon,
Cholesterol_ rings A-
D,At C3,there is a
hydroxyl group (OH)
as the head polar
group,It condenses
with fatty acids to
form a sterol ester for
storage and transport
Bile acids are poplar derivatives of cholesterol that acts like a
detergents in the intestine,emulsifying dietary fats to make them
readily accessible to digestive lipases,
Lipids as signals,cofactors and pigments
1) membrane- 5-10% dry mass of a cell,storage as 80% in
adipocytes.—both passive molecules—less exciting?
2) Third class of lipids are the active lipids; a) secondary
messengers (intracellular),hormones in the blood stream,
b) co-factors /enzymes in the electron-transfer reactions in
chloroplasts and mitochondria,or transfer of sugar moiety
in glycosylation,c) pigment molecules that absorb visible
light—light capturing in vision and photosynthesis,or
natural coloration—pumpkins,carrots,They all come from
membrane or vitamins such as A,D,E and K.
Phosphatidylinositols as
intracellular signals
Also binds to
cytoskeleton proteins
and those involved in
membrane fusion in
exocytosis
When stimulated by hormones,phospholypase A2 releases
arachidonic acid from membrane phospholipids,Arachidonic acid
is the precursor of various bioactive eicosanoids—prostaglandins,
PGE1,thromboxanes A2,and leukotrienes A4,
Arachidonic Acid and Eicosanoid derivatives
Bengt Samuelsson
and Sune
Bergstrom—regulate
cAMP synthesis in
response to
hormones,also SMC
contraction-labor,
blood flow,wake-
sleep cycle,PGE3
cyclooxygenase
NSAID,asprin,
acetaminophen,
ibuprogen
Jane Vane—made
by platelets-promote
blood clots and
reduce blood flow to
clot site
Released from
leukocytes,D4
induces contraction
of muscles lining the
airway to lung,
Overproduction—
asthmatics—target
for antiasthmatic
drug such as
prednisone
Hormones—messages
between tissues
Testosterone—made
in testes
Estradiol—ovaries
and placenta,
Cortisol and
aldosterone—cortex
of adrenal gland—
regulate glucose
metabolism and salt
excretion
Prednisone—
antiinflammatory drug
Vitamins– those are essential to health,but not synthesized by
them,thus,must be provided by food!
We will consider A,D,E,K,
Synthesis of vitamin D
Control calcium metabolism in
kidney,intestine,and bone
Vitamin A1,its precursors and derivatives
Two
molecules
Henrik Dam and Edward A Doisy– discovered that K
deficiency slows down clotting,
K1 undergoes a cycle of oxidation and reduction during the
formation of active prothrombin,Warfarin inhibits this process
Sugars are activated by attaching to isoprenoid alcohol-
dolichols; they are hydrophobic,thus,anchored on membrane to
provide the anchored sugar to the sugar transfer reactions.
Common Procedures in the extraction,
separation,and identification of
cellular lipids
Thank you!
