•Lipids are a class of biological molecules
defined by low Solubility in water and high
Solubility in non polar solvents such as
Benzene, Chloroform, toluene etc.
•Lipids are an important component of
living cells. Together with carbohydrates
and proteins.
•They are classified in to simple
,compound and derived lipids
What are lipids?What are lipids?
COMPOUND LIPIDSCOMPOUND LIPIDS
•These are Esters of fatty acids with
alcohol and posses additional group.
•For example: cerebrosides, glycolipids,
sulpholipids etc
•These are further divided into
Phospholipids
Glycolipids
•Phospholipids are compound containing
fatty acids and glycerol in addition to a
phosphoric acid, nitrogen bases and other
substituents.
•They are present in large amounts in
nerve tissue, brain, liver, kidney, pancreas
and heart.
•They are further classified into,
Glycerophospholipids and Sphingolipids.
PHOSPHOLIPIDSPHOSPHOLIPIDS
GlycerophospholipidsGlycerophospholipids
•Glycerophospholipids (phosphoglycerides)
are the major lipid components of biological
membranes.
•Glycerophospholipids are derivatives of
Phosphatidic Acid.
•Glycerophospholipids are amphiphilic
molecules with nonpolar aliphatic
(hydrocarbon) “tails” and polar phosphoryl-X
“heads.
•They act as surfactants, thus they help in
emulsification of fats.
They consist of glycerol-3-
phosphate esterified at C1
and C2 positions with fatty
acids. In addition, the
phosphoryl group is linked
to another usually polar
group , X .
a) The backbone, L-glycerol-3-
phosphate.
b) The general formula of the
Glycerophospholipids.
R1 and R2 are the long-chain
hydrocarbon tails of fatty
acids, and X is derived from a
polar alcohol.
•The simplest Glycerophospholipids, in
which X = H, are phosphatidic acids; they
are present in only small amounts in
biological membranes.
Phosphatidic acidPhosphatidic acid
Phosphatidic acidPhosphatidic acid
FATTY ACID
FATTY ACID
PP
Phosphatidic acids are Phosphatidic acids are
phospholipids which on phospholipids which on
hydrolysis give rise to hydrolysis give rise to
one molecule each of one molecule each of
glycerol and phosphoric glycerol and phosphoric
acid and two molecules acid and two molecules
of fatty acids.of fatty acids.
GlycerophospholipidsGlycerophospholipids
The Common Classes of GlycerophospholipidsThe Common Classes of Glycerophospholipids
• Phosphatidylethanolamines are a class
of phosholipids found in biological membranes.
•This phospholipid is composed of ethanolamine
as head group and glycerophosphoric acid,
with two fatty acids.
•Also called as Cephalin.
•Ethanolamine is a nitrogenous base present in
cephalin.
•The cephalins are closely associated with
lecithins in animal tissues.
PhosphatidylethanolaminPhosphatidylethanolamin
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R1 and R2 are fatty acid residuesR1 and R2 are fatty acid residues
• It can amount to 20% of liver phospholipids and It can amount to 20% of liver phospholipids and
as much as 45% of those of brain; higher as much as 45% of those of brain; higher
proportions are found in mitochondria than in proportions are found in mitochondria than in
other organelles. other organelles.
•Also called as Lecithin.
•This phospholipid is composed of a choline
head group and glycerophosphoric acid, with a
variety of fatty acids. Usually, one is a
saturated fatty acid and the other is an
unsaturated fatty acid .
PhosphatidylcholinePhosphatidylcholine
•They are widely in nature various oil seeds like
soyabeans and the yeasts are important source
from plants.
•They lecithins are required for the normal
transport & utilization of other lipids, especially
in the liver.
PhosphatidylserinePhosphatidylserine
•This phospholipid is composed of This phospholipid is composed of serineserine as as
head group and phosphoric acid with 2 fatty head group and phosphoric acid with 2 fatty
acids.acids.
• It plays a key role in It plays a key role in cell cycle signalingcell cycle signaling, ,
specifically in relation to specifically in relation to apoptosis.apoptosis.
• PhosphatidylserinePhosphatidylserine plays a role in plays a role in bloodblood
coagulationcoagulation (clotting).(clotting).
•Phosphatidylserine coming from plants and Phosphatidylserine coming from plants and
phosphatidylserine coming from animals differ in phosphatidylserine coming from animals differ in
fatty acid composition.fatty acid composition.
https://https://perfectketo.com/perfectketo.com/
phosphatidylserinephosphatidylserine//
CardiolipinCardiolipin
Diphosphatidylglycerol It consist of two It consist of two
molecules ofmolecules of
phosphotidic acid phosphotidic acid
held by anheld by an
additional glycerol additional glycerol
through phosphatethrough phosphate
groupgroup
FunctionFunction::
Plays a key role in Plays a key role in
apoptosis.apoptosis.
An important component of inner mitochondrial membrane.An important component of inner mitochondrial membrane.
PlasmalogensPlasmalogens
Plasmalogens Plasmalogens are glycerophospholipids in which the C1 are glycerophospholipids in which the C1
substituent of the glycerol moiety is linked via an alpha substituent of the glycerol moiety is linked via an alpha
and beta unsaturated ether linkage in the cis and beta unsaturated ether linkage in the cis
configuration rather than through an ester linkage.configuration rather than through an ester linkage.
Function:
•More resistant to oxidative stress therefore
provides protection to tissues with active
aerobic metabolism.
•Ethanolamine, choline, and serineEthanolamine, choline, and serine form the form the
most common plasmalogenmost common plasmalogen head groups.head groups.
•Plasmogen constitute about 10% of the Plasmogen constitute about 10% of the
phospholipids of the brain and muscle.phospholipids of the brain and muscle.
•The functions of most plasmalogens are not well The functions of most plasmalogens are not well
understood.understood.
Phosphatidylinositol Phosphatidylinositol
•PhosphatidylinositolPhosphatidylinositol is classified as a is classified as a
glycerophospholipid that contains a glycerol backbone, glycerophospholipid that contains a glycerol backbone,
two non-polar fatty acid chains, a phosphate group two non-polar fatty acid chains, a phosphate group
substituted with an substituted with an inositol inositol polar head group.polar head group.
•present in all tissues and cell types. Especially
abundant in brain tissue, (10% of the
phospholipids).
•Most important component of cell membrane.
Functions:
•Protein anchoring
•Membrane transport
•Secondary messanger
SphingophospholipidsSphingophospholipids
SphingophospholipidsSphingophospholipids
•Sphingolipids, Sphingolipids, the fourth large class of the fourth large class of
membrane lipidsmembrane lipids, , also have a polar head group also have a polar head group
and two nonpolar tails.and two nonpolar tails.
•but unlike glycerophospholipids they contain no but unlike glycerophospholipids they contain no
glycerol.glycerol.
• Sphingolipids are composed of one molecule of Sphingolipids are composed of one molecule of
the long-chain amino alcohol.the long-chain amino alcohol.
• sphingosine (also called 4-sphingenine) or one sphingosine (also called 4-sphingenine) or one
of its derivatives, one molecule of a long-chain of its derivatives, one molecule of a long-chain
fatty acid, and a polar head group that is joined fatty acid, and a polar head group that is joined
by a glycosidic linkage in some cases and a by a glycosidic linkage in some cases and a
phosphodiester in othersphosphodiester in others
When a fatty acid is attached in amide linkage When a fatty acid is attached in amide linkage
to the NHto the NH
22 on C-2, the resulting compound is a on C-2, the resulting compound is a
ceramideceramide..
Ceramide is the structural parent of all Ceramide is the structural parent of all
Sphingolipids.Sphingolipids.
SphingosineSphingosine
2-amino-4-octadecene-1,3-diol
C-18 alcohol containing two –OH groups, one
amino group and one double bond
SphingomyelinSphingomyelin
•SphingomyelinsSphingomyelins, the most common sphingolipids, , the most common sphingolipids,
are ceramides bearing either a are ceramides bearing either a phosphocholinephosphocholine or a or a
phosphoethanolamine head phosphoethanolamine head group.group.
•Constituent of the myelin sheath of nerve fibers.
•Although sphingomyelins differ chemically from
phosphatidylcholine and
phosphatidylethanolamine, their conformations
and charge distributions are quite similar.
•The membranous myelin sheath that surrounds
and electrically insulates many nerve cell axons
is particularly rich in sphingomyelins. .
Functions
•Building block of myelin sheath
•Primary source of ceramide
•Signal transduction(cell signaling)
FATTY ACID
O SINE
CARBOHYDRATE
Glycolipids/glycosphingoliGlycolipids/glycosphingoli
pidspids
Glycolipids/glycosphingoliGlycolipids/glycosphingoli
pidspids
Essential components of
all membranes in the
body. greatest amounts
in nerve tissue
Functions
regulation of cellular
interactions, growth, and
development
CEREBROSIDES
GLOBOSIDES
GANGLIOSIDES
SULFATIDES
CerebrosidesCerebrosides
•ceramide monosaccharides -simplest neutral
glycosphingolipids
•Galactocerebroside ,which are most common in
the neuronal cell membranes of the brain & have a
Beta –D- galactose head group.
•Glucocerebroside - serves primarily as an
intermediate in the synthesis and degradation of the
more complex glycosphingolipids.
•cerebrosides are found predominantly in the brain and
peripheral nervous tissue, with high concentrations in
the myelin sheath
GalactocerebrosideGalactocerebroside
GlobosidesGlobosides
•Globosides are glycosphingolipids with two or more
sugars, usually D-glucose, D-galactose, or N-acetyl-D-
galactosamine.
•Cerebrosides and globosides are sometimes called
neutral glycolipids.
•As they have no charge at pH 7.
Functions:
• It serves as an intermdiate in biosynthesis of
gangliosides
•It is responsible for the anitgenicity of blood
groups A and B.
•Gangliosides are the most
complex glycosphingolipids.
They are ceramides with
attached oligosaccharides that
include at least one sialic acid
residue.
•found primarily in the ganglion
cells of the central nervous
system, particularly at the nerve
endings.
GangliosidesGangliosides
•Gangliosides are primarily components of cell-surface Gangliosides are primarily components of cell-surface
membranes and constitute a significant fraction (6%) of membranes and constitute a significant fraction (6%) of
brain lipids.brain lipids.
•Gangliosides have considerable physiological and Gangliosides have considerable physiological and
medical significance.medical significance.
•Their complex carbohydrate head groups, which extend Their complex carbohydrate head groups, which extend
beyond the surfaces of cell membranes, act as specific beyond the surfaces of cell membranes, act as specific
receptors for certain pituitary glycoprotein hormones that receptors for certain pituitary glycoprotein hormones that
regulate a number of important physiological functions.regulate a number of important physiological functions.
•Gangliosides are also receptors for certain bacterial Gangliosides are also receptors for certain bacterial
protein toxins such as protein toxins such as cholera toxin.cholera toxin.
•cerebrosides that contain
sulfated galactosyl
residues
•negatively charged at
physiologic pH
•found predominantly in
nerve tissue and kidney
SulfatidesSulfatides
DiseasesDiseases
•Sphingolipidoses are a class of lipid storage
disorders relating to sphingolipid metabolism.
• The main members of this group
are Niemann–Pick disease, Fabry
disease, Krabbe disease, Gaucher
disease, Tay–Sachs disease etc.
SphingolipidosisSphingolipidosis
•Is caused by the deficiency of the enzyme
glucocerebrosidase.
• Fatty material can collect in the brain, spleen, liver,
kidneys, lungs, and bone marrow.
•It affects an estimated 1 in 50,000 to 1 in 100,000
people in genral population.
•Ashkenazi jews are at high risk.
•Gaucher disease has three common clinical
subtypes they are Type 1 , Type 2 & Type 3.
Gaucher diseaseGaucher disease
•Symptoms vary depending on the type of disease,
but may include:
Bone pain and fractures
Easy bruising caused by a decrease in blood
platelets (Thrombocytopenia).
Enlarged spleen (splenomegaly)
Enlarged liver (hepatomegaly)
Fatigue
Heart valve problems
Lung disease
SymptomsSymptoms
SeizuresSeizures
Severe swelling (Severe swelling (edemaedema) at birth) at birth
A low number of RBC (A low number of RBC (AnemiaAnemia))
yellow spots in the eyesyellow spots in the eyes
Liver malfunctionLiver malfunction
Skeletal weakness and bone disease Skeletal weakness and bone disease
may be extensive.may be extensive.
Enlarged spleenEnlarged spleen
HepatosplenomegalyHepatosplenomegaly
(enlargment of both (enlargment of both
liver and spleen)liver and spleen)
•The doctor will perform a physical exam.
•The patient may have signs of liver and spleen
swelling, bone changes, lung disease, eye
movement problems, heart problems & hearing
loss.
•Blood test to look for enzyme activity(measurement
of glucocerebrosidase activity)
•Bone marrow examination for the presence of
Gaucher’s cells is diagnostic
• Biopsy of the spleen and liver.
DiagnosesDiagnoses
•MRIMRI is more accurate than ultrasonography in is more accurate than ultrasonography in
determining organ sizedetermining organ size..
RadiographyRadiography Skeletal radiography can be used to Skeletal radiography can be used to
detect detect and evaluate skeletal manifestations of Gaucher and evaluate skeletal manifestations of Gaucher
disease.disease.
• Enzyme replacement treatment given
intravenously (via injection) every two weeks can
dramatically decrease liver and spleen size,
reduce skeletal abnormalities, and reverse other
manifestations.
•Bone marrow transplant is also helpful.
•Blood transfusion may benefit some anemic
individuals.
TreatmentTreatment
Niemann-Pick diseaseNiemann-Pick disease
•Autosomal recessive
disease .
•Excessive accumulation
of sphingolipids .
•Affects 1 out of 150,000
births, hence its rare.
•It is a type of lipid storage
disease
•Its is divided in to 3 types
Type A,B and C
Niemann type A & BNiemann type A & B
• • It is caused by mutation in gene It is caused by mutation in gene SMPD1 SMPD1
((Sphingomyelin Phosphodiesterase 1Sphingomyelin Phosphodiesterase 1).).
• • SMPD1 gene carries instructions for cells to produce SMPD1 gene carries instructions for cells to produce
sphingomyelinase which processes lipids.sphingomyelinase which processes lipids.
••The most severe form, begins in early infancy. Infants The most severe form, begins in early infancy. Infants
appear normal at birth but develop profound brain appear normal at birth but develop profound brain
damage by 6 months of age.damage by 6 months of age.
Niemann type C1 & C2Niemann type C1 & C2
•It is caused by mutation in a gene NPC1 andIt is caused by mutation in a gene NPC1 and
NPC2 (NPC2 (Niemann pick C1 and C2 respectivelyNiemann pick C1 and C2 respectively))
•NPC1 gene produces a protein involve in theNPC1 gene produces a protein involve in the
•movement of cholestrol and lipids within cells.movement of cholestrol and lipids within cells.
• NPC2 gene produces protein that binds andNPC2 gene produces protein that binds and
•transport cholestrol.transport cholestrol.
•Enlargement of liver (hepatomegaly) may cause
reduced appetite, abdomen distension and pain.
•Enlargement of spleen(spleenomegaly) may also
cause low levels of platelets in the blood
(thrombocytopenia).
• Accumulation of sphingomyelin in CNS results in
slurring of speech , difficulty in swallowing
(dysphagia), abnormal posturing of limbs trunk and
face.
•Bones may also affected : Enlarged bone marrow
cavities
SymptomsSymptoms
ASM (aspartame)ASM (aspartame)
•No specific treatment is known but symptoms can be
treated.
• In adult patients with type B, physicians try to keep
cholestrol level down to normal level.
• Used statins to monitor liver function.
• If spleen is enlarged and platelets level are low ,
acute episodes of bleeding may require transfusion of
blood products.
• Organ transplant has been attempted with limited
success.
TreatmentTreatment
• Gene therapies, enzyme therapies and bone marrow Gene therapies, enzyme therapies and bone marrow
transplantation.transplantation.
• A drug A drug Zavesca Migulstat Zavesca Migulstat has been approved in has been approved in
European union for treatment of neurologicalEuropean union for treatment of neurological
manifestations of Niemann pick disease type C.manifestations of Niemann pick disease type C.
Write the short notes on the follwing (3 marks)
1.Phospholipids
2.Lecithin
3.Sphingolipids
4.Ceramide
5 marks questions
1.Give an account of lipid Classification
2.Elaborate on the classification and properties of
lipids.
Previous asked questionsPrevious asked questions