Neutral fats act as surfactants and detergents. They are soluble in water and components of cell membranes. Major forms of lipid storage in the body include triglycerides. Compound lipids include phospholipids, which contain a glycerol backbone, two fatty acid chains, and a phosphate group attached to a nitrogenous base. Glycolipids contain a ceramide backbone with attached carbohydrates. Lipoproteins package and transport lipids through the bloodstream, and are composed of a hydrophobic core of triglycerides and cholesterol esters surrounded by a hydrophilic outer layer containing phospholipids, free cholesterol, and apolipoproteins.

1. Believe yourself
Simple &
Compound Lipids
By
Dr. Santhosh Kumar N
Associate Professor

2. Neutral fats are
a) Act as surfactant & detergents b) Soluble in water
c) Components of bio membranes d) Oxidized to give energy
Naturally occurring unsaturated fatty acids exist as
a) Cis isomers b) Trans isomers c) Cis & Trans isomers d) none of the above
Major storage form of lipid is
a) Esterified cholesterol, b) Glycerophospholipids c) Triglyceride d) Sphingolipids
Omega -3 fatty acids used for boosting memory is
a) Timnodonic (EPA), b) Arachidonic acid, c) Cervonic acid (DHA) d) clupanodonic
Glycerophospholipids contains alcohol
a) Spingosine, b) cholesterol, c) cholesterol ester d) Glycerol
Which EFA helps to make the skin impermeable to water
a) Linolenic acids , b) Linoleic acids, c) Arachidonic acid, d) Cervonic acid
Linoleic acid + cerebrosides →acyl-glucosylceramide

3. • A teenager, concerned about her weight, attempts to maintain
a fat free diet for a period of several week. If her ability to
synthesized various lipids were examined, she would be
found to be most deficient in his ability to synthesize
A) Cholesterol,
B) Glycolipids
C) Phospholipids
D) Prostaglandins
E) Triacylglycerol
Prostaglandins formed from
arachidonic acid ← formed from
linoleic acid (is an EFA) - obtained
by human from dietary lipids

4. Triglycerides / Triacylglycerols
 TG is a storage lipid in animal (cytoplasm of adipose cells)
 Oxidized to give energy.
 Fat stored under the skin serve as an insulator against coldr against cold
Tri-glyceride (TG)
Glycerol Mono-glyceride Di-glyceride

5. Depending upon the fatty acid residues in glycerol,
- simple triglycerides
- mixed triglycerides
E.g. Olive oil, the fatty acid is oleic
acid then it was named as triolein.
In Human fat, mixed triglycerides

6. Properties
of
Triglycerides

7. Hydrolysis
During digestion of fat in the GI tract .
7

8. Saponification
 Hydrolysis of TGs by alkali to produce glycerol & alkali salts of the FAs.
TGs + 3 KOH Glycerol + 3 R- COOK (soaps)
• Soaps are good cleaning agents, germicides & detoxicants

9. Hydrogenation (Chemical Process)
 Used to convert liquid fats of plant origin to solid cooking fats
eg: Vanaspati (dalda) – obtained from vegetable oils
Natural Unsaturated fats Saturated fats

10. Rancidity
 The unpleasant smell and taste of natural
fats or oils
 Due to partial hydrolysis of TG (or)
oxidation of PUFA
 Caused by more exposed to air, moisture,
light, & bacteria
 USFA are more susceptible to oxidative
rancidity than saturated fatty acids.
Fat containing unsaturated FAs
Polymerization of cyclic
hydrocarbons
Disagreeable odor.
partial hydrolysis /
Oxidation
leads to

11.  It disturb the assembly of the membrane,
causing changes in fluidity & permeability,
alterations of ion transport and inhibition of
metabolic process.
 Injure to mitochondria can further
generates ROS.
Lipids
Epoxides, peroxides, enediols &
free radicals
Affect the integrity of bio-
membranes
Inflammatory diseases,,
Atherosclerosis, ageing &
cancer
Causes
Oxidation
Lipid Peroxidation (In vivo)

12. Antioxidants
The substances, which can prevent the occurrence of oxidative rancidity & free radical
formation.
- Naturally occurring antioxidants - Vitamin-C
- Vitamin-E (Tocopherol)
- Pro vit-A (β-carotene)
- Food additives such as – Propyl gallate
- Butylated hydroxy anisole (BHA)
- Butylated hydroxy toluene ( BHT)

13. “CHARACTERISATI
ON
OF
FATS & OILS”

14.  Adulteration of fats & oils is increasing day by day.
 Several tests are employed in the laboratory to check the purity of fats &
oils.
• Iodine number
• Saponofication number
• Reichert-Meissl (RM) number
• Acid number

15. Iodine Number Saponification
Number
Reichert Meissl
Number (RM
Number)
Acid Number
to assess the degree
of USFA of fat or
oils and also to
check the purity &
nutritive value of
fats & oils
It measure the
average molecular
wieght & chain
length of the FAs
present
To assess the purity
of fats having more
volatile fatty acids
• It indicates the
degree of
rancidity of fats
and oils.
The no of grams of
iodine absorbed by
100g of fat.
Iodine number is
directly proportional
to the content of
USFA.
Number of mgs of
KOH required to
saponify one gram
of fat or oil.
The no. of ml of
0.1N KOH required
to completely
neutralize the
soluble volatile fatty
acids distilled from
5g of fat or oil.
mg of KOH
required to
completely
neutralize free fatty
acids present in 1gm
of fat or oil.

16. Phospholipids Glycolipids Lipoproteins
COMPOUND LIPIDS

17. PHOSPHOLIPIDS
• Esters of fatty acids containing Phosphoric acid , nitrogenous bases and other
substitution groups.
G
L
Y
C
E
R
O
L
FATTY ACID
FATTY ACID
Phosphoric acid Nitrogenous Base
Amphipathic nature

18. Polar head
Hydrophilic region
Non polar Tails,
Hydrophobic region

19. G
L
Y
C
E
R
O
P
H
O
S
P
H
O
L
I
P
I
D
S
Phosphatidyl Choline (Lecithin)
Phosphatidyl Ethanolamine
(Cephalin)
Phosphatidyl inositol
Phosphatidyl serine
Plasmalogens
Phosphatidylglycerol (Cardiolipin)
S
P
H
I
N
G
O
P
H
O
S
P
H
O
L
I
P
I
D
S
Sphingomyelins
Phospholipids
based on the type of
nitrogenous base & alcohol
2 types

20. Lecithin ( Phosphatidyl choline)
 Most abundant phospholipid in the cell membranes.
 Containing labile CH3 groups involved in methylation reactions.
 Storage form of choline in body
 Act as lipotropic factor & anti-cholesterol agent
O
O
H2C O C R
O
R C O CH
H2C O P O CH2 CH2 N
+
CH3
CH3
CH3
O_
Phosphatidic Acid Choline
Nitrogenous bases

21. Lecithin ( Phosphatidylcholine)
Dipalmitoyl lecithin
Lysolecithin
 Found in lungs & act as lung
surfactant
 Defect leads to Acute pulmonary
respiratory distress syndrome in
infants.
-It formed by removal of the FA
either at C1 or C2 of lecithin
-Component of cobra venom & a
strong hemolysing agent.

22. Dipalmitoyl lecithin secreted by
pulmonary type-II epithelial cells and
surrounds the alveoli of the lungs
To prevent lung collapse during
breathing
It decreases the surface tension of
the lungs
In premature infant
Due to immature lungs,
Dipalmitoyllecithin do not syn enough
Collapse of the alveoli of lungs
Role of Dipalmitoyl lecithin (lungs surfactant)
Decreased oxygenation of blood &
tachypnoea (abnormal rapid breathing)
In normal conditions Respiratory distress syndrome

23. Lecithin / Sphingomyelin (L/S) ratio
 L/S ratio is a test of fetal amniotic fluid to assess for fetal lung immaturity
 A ratio of > 2.0 is evidence of pulmonary maturity.
 < 2.0 is indicate immature fetal lung development
 Administration of natural or synthetic surfactant is used in the prevention & treatment
of respiratory distress syndrome

24. Cephalin (phosphatidylethanolamine)
• Involved in blood clotting process
• Increase the rate of thrombin formation by promoting binding of factor –V, VIII & X)
Ethanolamine
Nitrogenous base

26. Phosphatidylinositol
• The myoinositol is attached to phosphatidic acid to form PI
• Act as second messenger & stimulates oxytocin &vasopressin.
• It helps to release of calcium
O P
O
O
H2C
CH
H2C
O
C
R1
O O C
O
R2
OH
H
OH
H
H
OH
H
OH
H
O
H OH
phosphatidyl-
inositol

27. Phosphatidylserine
• Component of the cell membrane of brain & RBCs
• Plays a key role in cell cycle signaling pathways
• Act as a signal for macrophages to engulf the cells
serine

28. Phosphatidylglycerol (Cardiolipins)
• Imp component of inner mitochondrial membrane, involved in cellular
respiration.
• Act as an Antigenic properties (Any substance that causes immune system to
produce Antibodies against it).

29. Plasmalogens
• Found in bio-membranes of brain & muscles.
• Involved in the membrane bilayer formation & antioxidant function
α, β unsaturated FA

30. SPHINGO
PHOSPHOLIPIDS
Alcohol as a sphingosine in phospholipids
Rich in myelin sheath of nerve cell

31. Sphingosine + Fatty acid = Ceramide
Ceramide + Phosphoryl group + Nitrogenous base = Sphingomyelin
Structural lipids of membranes of nerve tissues &Protects neural fibres & myelin sheath
Regulates enzyme systems like protein kinase & protein phosphatase

32. 2. GLYCOLIPIDS Ceramide Carbohydrate
Phosphoric acid group
Essential components of cell or
plasma membranes (outer leaflet)
& nervous tissues

33. Glycolipids Composition Functions
Cerebroside Ceramide + Mono-
saccharides
- Provide protective coating to
each nerve and act as insulator
- Act as cell membrane receptors
for polypeptide hormones.
- Act as surface receptors for
some toxins & viruses.
- Antigenic property
- Mediating cell-cell recognition
& cell interactions
Sulfatides Ceramide + Mono -
saccharides + Sulfate
Globosides Ceramide + Oligo -
saccharides
Gangliosides Ceramide + Oligo-
saccharides + N–acetyl
neuraminic acid

34. 3. LIPOPROTEINS
Protein
Lipid
Apoprotein

35. It composed of triglyceride and cholesterol ester core &
surrounded by single lipid layer containing phospholipid
and free cholesterol & a shell of proteins.

37. Structure & Composition of Chylomicrons
Protein
%
CH
%
TG
%
PL
%
Apo
proteins
Site of syn Functions
2 4 85 9 Apo-A,
B48, C-II
& E
Intestine Transport of dietary TGs and
cholesterol esters from
intestine to peripheral tissues
and liver.

38. Very low density lipoproteins (VLDL ) /
IDL
Protein
%
CH
%
TG
%
PL
%
Apo
proteins
Site of
syn
Functions
10 15 55 20 Apo-B100, C
&E
Liver Transports endogenous TGs
from liver to peripheral tissues.

39. Low Density lipoprotein (LDL)
Protein
%
CH
%
CE
%
TG
%
PL
%
Apo
proteins
Site of
syn
Functions
20 10 40 8 22 Apo-
B100
Plasma
VLDL
Transports cholesterol
from liver to peripheral
tissues.
50%

40. P
%
C
%
CE
%
TG
%
PL
%
Apo
proteins
Site of
syn
Functions
40 2 23 5 30 Apo-A,
C-II & E
Liver &
Intestine
1) Transports cholesterol from
peripheral tissues to liver.
2) Serves as a circulating reservoir of
Apo C-II & E
3) Transfers cholesteryl esters to VLDL
& LDL in exchange for TG & PL from
these particles
High-Density Lipoprotein
(HDL)
25%

41. Apoproteins and its functions
Lipoprotein Apoprotein Functions of apoproteins
Chylomicrons Apoprotein -A, B-48, C-II
& E
•Maintaining the structural integrity
of the lipoproteins
•Responsible for recognition of
particle by receptors
•Regulating certain enzymes, which
act on the lipoproteins
VLDL Apoprotein- B-100, C-I,
II, III & E
IDL Apoprotein - B-100 & E
LDL Apoprotein -B-100
HDL Apoprotein - A, C-II, D
& E

42. Thank You