Storage Lipids

1. 1.Butter 2.Olive Oil 3. Bees Wax

2. LIPIDS : INTRODUCTION
•Biological lipids are diverse group of chemicals having
common defining property of insolubility in water.
•Two major categories of lipids are
1) Storage lipids
2)Membrane lipids
•Other lipids are present in relatively small amounts yet
play crucial roles as
a) Enzyme cofactors, b) electron carriers, c)light-
absorbing pigments, d) hydrophobic anchors for
proteins "chaperons” to help membrane proteins fold,
e) emulsifying agent in the digestive tract, f) intracellular
messenger, g) harmones.

3. STORAGE LIPIDS:INTRODUCTION
Storage lipids or neutral lipids:- The simplest lipids
constructed from unbranched fatty acids usually of even
number of carbon atoms are triglycerides , also known as
triacylglycerol , animal fat and vegetable oil etc. These are
composed of three fatty acids each in ester linkage with a
single glycerol . The general formula of fats and oils is given
below-

4. STORAGE LIPIDS-NOMENCLATURE
•Lipids containing the same kind of fatty acids in all
three positions are called simple triacylglycerols and are
named after the fatty acids they contain. Simple
triacylglycerols of 16:0,18:0, and 18:1, for example , are
tripalmitin, tristearin and triolein, respectively.
Tripalmitin Tristearin Triolein

5. STORAGE LIPIDS-NOMENCLATURE
•Normally naturally occurring lipids contain mixture of fatty
acids in a molecule ,ie. they contain two or three fatty acids.
•For the naming of such a molecule the name and position of
each fatty acid is specified for eg. a mixed triacylglycerol
named 1-Stearoyl, 2-linoleoyl, 3-palmitoyl glycerol, contains
one glycerol and three different fatty acids at C-1 , C-2 and C-
3 positions. Structures of two such lipids are drawn below-
Oleodipalmitin Oleopalmitostearin
(α-Oleo-β,α-dipalmitin) (α-oleo-β-palmito -α/-stearin)

6. STEREOISOMERISM IN LIPIDS
Leaf abscission
When the groups attached to C-1 and C-3 differ a centre of
asymmetry is created at C-2 .The two optical isomers may,
thus, be represented as follows. The naturally occurring
fats are L-type.
D-isomer L-isomer

7. PHYSICOCHEMICAL PROPERTIES OF FATS AND OILS
The physicochemical and chemical properties: of a fat or oil are determined by
the ratio of its component saturated and unsaturated acids.
•Triglycerides have lower densities than water(they float on water).
•At normal room temperature they may be solid or liquid. When solid , they
are called “fats” or “ butters” and when liquid they are called “oils” .
•Fats and oils are insoluble in water and readily soluble in organic solvents;
they are usually slightly soluble in alcohol.
•When treated with superheated steam, inorganic acid or alkali fats undergo
hydrolysis( saponification ) with the formation of glycerol and fatty acids or
their salts.
•Emulsions are formed by vigorous agitation with water. An example of a
stable aqueous fat emulsion is milk. The emulsification of fats in the intestines
(a necessary condition for their absorption) is effected by salts of bile acids.
•Fats are main energy source of the body . The energy value of fats is more
than twice as great as that of carbohydrates
•Fat deposits in skin provide the pronounced elasticity

8. •The fats have extremely low heat conductivity and thus the fat deposited in the subcutaneous fatty
cellular tissue acts as heat insulator, protecting the body from heat loss which is particularly useful for
warm –blooded marine animals such as whales and seals.
•The fat content of human body and of animals varies greatly. In cases of great corpulence and of
hibernating animals before hibernation, the fats content of the body reaches 50%. Similarly when farm
animals are fattened, their fat content is particularly high.
•In the body a distinction is made between reserve fats, which are deposited in the subcutaneous
fatty cellular tissue and in the omentum, and protoplasmic fat, which is a component of protoplasm in
the form of complexes with proteins, called lipoproteins. In case of starvation or inadequate feeding,
the reserve fat disappears, but the percent of protoplasmic fat in the tissues stays almost the same,
even when the body is extremely emaciated.
•Organic solvents readily extract reserve fat from fatty tissue. Protoplasmic fats can be extracted
from fatty tissue with organic solvents only if the tissues have been previously treated to denature
the proteins and split up their complexes with fats.
•In cooking the “smoke” point of an oil or fat is the temperature at which , under defined conditions,
enough volatile compounds emerge from the oil that a bluish smoke becomes clearly visible. At this
temperature, volatile compounds, such as water, free fatty acids, and short-chain degradation
products of oxidation come up from the oil. The smoke point is the temperature at which the oil is
decomposed and where possibly toxicologically relevant compounds are formed. Considerably above
the temperature of the smoke point is the “Flash point”, the point at which the vapors from the oil
can first ignite when mixed with air.
PHYSICOCHEMICAL PROPERTIES OF FATS AND OILS

9. CHARACTERISATION OF FATS
Fats are characterized and their purity or otherwise assessed by determining certain
chemical constants for individual fats-
SAPONIFICATION– Number of mgs of KOH required to neutralize the free and combined
fatty acids in a gm of a given fat is its saponification number. A high saponification number
indicates that the fat is made up of low molecular weight fatty acids and vice versa.
IODINE NUMBER - is the number of gms of Iodine required to saturate 100 gms of fat .Since
Iodine is taken up by the double bonds , a high Iodine number indicates a high degree of
unsaturation of the fatty acids of the fat.
ACID NUMBER – Number of mgs of KOH required to neutralize the free fatty acids in a gm of
fat is known as acid number .The acid number indicates the degree of rancidity of the given
fat .
REICHERT – MEISSL( R.M. )NUMBER – The number of ml of 0.1 N alkali required to neutralize
the volatile fatty acids ( separated by saponification , acidification and steam distillation of
the fat ) contained in 5 gms of the fat is the R.M. number

10. Categories of Storage Fats and Oils
Natural fats are subdivided into animal and vegetable fats. Plants contain relatively small
quantities of fats. Exceptions are oil producing plants, whose seeds differ in that they have
high oil content.
Animal fats and oils: These are lipid materials derived from animals. Physically, oils are
liquid at room temperature, and fats are solid. Chemically, both fats and oils are composed
of triglycerides.
In consumer products in U.S. animal remains are found to be classified as animal fats once
the particle size of bone solids is more than 3 percent, protein content is less than14
percent and or the product contains over 30 percent pure fat content.
Although many animal parts and secretions may yield oil, in commercial practice, oil is
extracted primarily from rendered tissue fats obtained from live-stock animals like pigs,
chicken and cows. Dairy products also yield popular animal fat and oil products such as
cheese, butter, and milk.
Animal fats are largely used in the production of margarine, shortening and compound fat.
They also enter into many processed food products. Industrial and non-food uses of animal
fats include the production of soaps, fatty acids, lubricants and feedstuff.
Animal fats are thus distinguished between edible fats and inedible fats. Edible fats used in
food frying processes are called “Used Cooking Oils”. Inedible fats are used only in pet
food, oleochemistry, biodiesel or to generate energy.

11. Animal Fats and Oils
A list of animal fats and oils is given below with the description of their nature and uses:-
Animal Fats and oils Description
 Lard Pig fat; both in its rendered and unrendered forms, it was
commonly used as cooking fat or shortening or as spread
similar to butter. Now a days it is not used much.
 Milk, butter Dairy products are animal secretions which contain varying
levels of water, oil, ’fats and animal cells from circulatory
and lymphatic systems such as blood and mammary
glands.

Goose fat
Produce a higher smoke point than other animal fats, but
are still lower than many vegetable oils .
 Greases Inedible lard.
 Tallow Obtained from suet (the hard white fat on the kidneys and
loins of cattle, sheep, and other animals) and used in
making soap, candles, and lubricants. Beef fat is edible and
is used for other purposes too.

12. Animal Fats and Oils
 Lanolin, wool- fat A yellow viscous animal oil extracted from wool; a mixture
of fatty acids and esters; used in some ointments and
cosmetics
 Dippel’s oil Dark colored ill-smelling oil obtained by carbonizing bone.
.
 Bone oil Used in lubricant and in leather manufacture
 Cod liver oil An oil obtained from the livers of cod and similar fishes;
taken orally as a sources of vitamins D &A.
 Halibut-liver oil A fatty oil from halibut livers that is used as a source of
vitamin A.
 Lard oil Oil consisting chiefly of olein that is expressed from lard and
used especially as lubricant, cutting oil or illuminant
 Menhaden oil A fatty oil obtained from the menhaden fish and used in
paint and ink and in treating leather.

13. Animal Fats and Oils
 Neat’s –foot oil A pale yellow oil made from feet and legs of cattle; used as
dressing for leather.
 Oleo oil Obtained from beef fat; used in making margarine and
soap and in lubrication.
 Porpoise oil A yellow fatty oil obtained from porpoises and used as a
fine lubricant.
 Dolphin oil An unsaturated fatty oil obtained from dolphins and used
as a fine lubricant.
 Sardine oil Oil obtained from sardines and chiefly as a lubricant and in
soap.
 Salmon oil A fatty oil obtained from the wastes in canning salmon;
used in making soaps and dressing leather.
 Seal oil A pale yellow to red-brown fatty oil obtained from seal
blubber; used in making soap and dressing leather and as
lubricant.
 Shark oil, shark- liver
oil
A fatty to yellow to brown oil obtained from livers of
sharks; used for dressing leather and as a source of
vitamin A.
 Sperm oil An animal oil found in the blubber of the sperm whale.

14. Vegetable oils and fats
•Both tropical and temperate plant families contain fatty oils.
•They are stored, frequently in large amounts, in seeds and somewhat in fruits
, tubers, stems and other plant organs. They may also contain proteins.
•This kind of reserve food material is available as a source of energy for the
processes involved in seed germination.
• Fatty oils are bland and lack the strong taste , odor and antiseptic qualities of
essential oils. Thus they are suitable for human food.
•These edible oils contain both solid and liquid fats and form an important part
of the human diet.
•With some exceptions, and in contrast to animal fats, vegetable oils contain
predominantly unsaturated (light, liquid) fatty acids of two kinds:
monounsaturated (oleic acid- mainly in extra virgin olive oil) and
polyunsaturated (linoleic acid and linolenic acid-in oils extracted from
oilseeds).

15. Vegetable oils and fats
•Industrial and non food uses of vegetable oils include the production of soaps,
detergents, fatty acids, paints, varnish resin , plastic and lubricants.
•Vegetable oils have a wide variety of food uses, including salad and cooking
oils as well as in production of margarine, shortening and compound fat. They
also enter into many processed products, such as mayonnaise, mustard, potato
chips, French fries, salad dressing, sandwich spread and canned fish.
•Extraction of fatty oil varies. Usually the seed coats have to be removed and
then the remainder is reduced to a fine meal. The oils are removed by solvents
or by subjecting the meal to hydraulic pressure. The residue is rich in proteins
and is valuable as an animal food and fertilizer. Pressure causes the cell wall to
break and the fats are released. The extracted oils are filtered and may be
further purified . Higher grades are edible and lower grades may be used in
various industries. Fatty oils may also have medicinal value.

16. Classes of plant fatty oils
Four classes of plant fatty oils are-
•Drying oils:-. these can absorb oxygen and on exposure dry into thin elastic films.
Such oils are important in the paint and Varnish industries.
•Semidrying oils:-these oils absorb oxygen slowly and only in small amounts. They
form a soft film only after long exposure to air. Some are edible; others are used
as illuminants or in making soaps and candles.
•Nondrying oils:- These remain liquid at room temperature and do not form a film.
Such oils are edible and may be used for soap and lubricants.
•Fats or Tallows:-these remain solid or semisolid at room temperature. They are
edible and also useful in the manufacture of soap and candles.
Drying and semidrying oils are more common in plants of temperate climates,
while nondrying oils and fats predominate in plants of tropical areas.
Classes of plant fatty oils

17. Given below is a list of examples of Drying oils :-
Name of oil Description
Drying oils these can absorb oxygen and on exposure
dry into thin elastic films. Such oils are
important in the paint and Varnish
industries
Examples:-
Linseed oil Flax seed, Linum usitatissimum, has been
the source of one of the most important
drying oils. The oil content in seed is 32-43
percent. It is yellow to brown in color, has
an acrid taste and smell, forms a tough
elastic film when oxidized and is used
mainly in making paints, varnishes,
linoleum, soft soap and printer’s ink.
Following oil extraction from seed, the oil
cake can be used as an animal feed.
A List of examples of Drying oils

18. A List of examples of Drying oils
Tung oil/Chinawood oil This is obtained from the seeds of the two
Chinese species of Alurites.
Oil is used in varnish industry and as a substitute
of linseed oil. It is used for waterproofing wood,
paper, and fabrics. It is a good preservative and is
resistant to weathering, so it is especially valuable
for painting outdoors. Boatmen have sought after
tung oil because it is little affected by water.
Large quantities were also used in producing
linoleum, oilcloth, brake lining, soap, leather
dressings, inks, insulating compounds and
fiberboard. The oilcake is a good fertilizer but is
unsuitable as an animal feed.
Soybean oil Glycine max is native to China and has been most
important food plant in Eastern Asia. The oil is midway
between linseed and cottonseed in its character.
Refined oil is used in salads or as cooking oil. Margarine,
tofu, ice cream substitute, vegetable meat substitute
etc are made from soybean. Oil is also used in making
soap, candles, varnishes, lacquers, paints, linoleum,
greases, rubber substitutes, cleaning compounds,
disinfectants and insecticides. The oil cake has 40-48
percent protein content and is valuable as a meat
substitute and feed for livestock. It is also used for
adhesives, plastics, foaming solutions, spreaders,
fertilizers, sizing, synthetic textiles etc.

19. A List of examples of Semidrying oils
Name Description
Semidrying oils
These oils absorb oxygen slowly and only in
small amounts. They form a soft film only
after long exposure to air. Some are edible;
others are used as illuminants or in making
soaps and candles.
Examples:-
Cottonseed oil Most important of the semidrying oils, and it
is used as the standard of comparison. The
pure refined oil is used for salads and
cooking oil and for making margarines and
lard substitutes. For industries it is the
source for soap, oilcloth, washing powders,
artificial leather, roofing tar, insulating
materials, putty, glycerin and nitroglycerin.
Cottonseed meal is important as a food for
animals and as a fertilizer.
List of examples of Semidrying oils is given below:-

20. A List of examples of Semidrying oils
Corn oil There is about 50 percent oil located in the embryo of
the maize kernels. Refined oil is used for human
consumption either directly or in margarines, while the
crude oil has industrial uses such as the rubber
substitutes, paints, soaps. Corn oil has little lubricating
value.
Sesame oil Also known as gingerly oil, sesame oil is the product of
an annual herb,Sesamum indicum.Seeds contain about
50 percent oil that is easily extracted by cold pressure.
The finer grades of oil are used as a substitute for olive
oil in cooking and in medicine. It is also used in the
manufacture of margarine and other foods. Poorer
grades of oil are used for soap, perfumery and rubber
substitute and sometimes as a lubricant. Oil cake is a
good cattle -feed, and sesame seeds are also used in
confectionery and baking industry.
Sunflower Helianthus annuus seeds contain 32-45 percent of light
golden-yellow oil equal to olive oil in its medicinal and
food value. It is an excellent salad oil and is used in
margarines and lard substitutes. The seeds are a
nutritious bird and poultry food, while the oil cake is
excellent for livestock and the whole plant is often
grown for silage. The oil has semidrying properties
rendering it useful in the varnish, paint and soap
industries.

21. A List of examples of Nondrying oils
A list of examples of nondrying oils is given below:-
Name Description
Nondrying oils
These remains liquid at room temperature and
do not form a film. Such oils are edible and
may be used for soap and lubricants.
Examples
Olive oil The fruits of the olive, olea europaea , provide
olive oil, and it is the most important of the
nondrying oil. The oil is golden yellow, clear
and limpid. Used chiefly as salad and cooking
oils , in canning sardines and in medicine.
Inferior grades have greenish tinge and are
used for soap making and as lubricants. It is
one of the most important food oils as it can
be stored for long periods and becomes rancid
only when exposed to air. The oil cake is used
for stock feed and as a substitute for humus in
soil conditioning.

22. A List of examples of Nondrying oils
Peanut oil Seeds of the common peanut, Arachis
hypogaea , provide peanut oil. Refined oil is
edible and used as a salad oil, for cooking , for
packing sardines, in making margarines and
shortenings, and as an adulterant for olive oil.
Inferior grades are for soap making, lubricants,
and illuminants. The oil cake is an excellent live
stock feed as it has higher protein content than
any other similar product.
Castor oil Seeds of Ricinus communis furnish versatile oil.
It is a colourless or greenish oil that is used in
medicine as purgative. Being water resistant it
may be used for coating fabrics and for
protective covering for airplanes, insulation,
food containers, firearms etc. It is an excellent
lubricant especially for airplane engines. When
hydrated it is converted into a quick-drying oil
used in paints and varnishes. It may also be
used in making soap, inks and plastics, for
preserving leather and as an illuminant. The
oilcake is poisonous but makes an excellent
fertilizer.

23. A List of examples of Vegetable fats and Tallows
List of examples of vegetable fats is given below:-
Names Description
Vegetable fats and Tallows These remain solid or semisolid at
room temperature. They are edible
and also useful in the manufacture of
soap and candles.
Coconut oil A widely used fatty oil, obtained from
dried white interior of the seeds of
Cocos nucifera. This is pale yellow or
colourless and is solid below 74 deg.
Fahrenheit. Refined oil is edible. It is
especially adapted for the purpose of
margarine as it is solid at room
temperatures. It is used for candy
industry and for making highest
quality soaps, cosmetics, shaving
creams, shampoos and suntan lotions.
It is used for marine soaps and as an
illuminant. The cake is an excellent
livestock feed.

24. A List of examples of Vegetable fats and Tallows
Palm oil It is a white vegetable fat that is solid at room
temperature and which is obtained from Elaeis
guineensi
Palm kernel oil This is a white vegetable fat that is solid at
room temperature. It is brownish red in
colour, it is used making soap and in
manufacture of tin plate, tern plate and cold
reduced sheet steel. The refined oil is used
in margarine and vegetable shortenings. It
has also been used as a fuel for diesel motors
in Africa. This fat like coconut fat has
saturated fatty acids and so now a days used
less as food.
Babassu oil It is the most important of the New World
palm oils and is obtained from the babassu
palm. Oil is expressed from kernels and when
refined it is used as a substitute for coconut
oil. It is used in making bulletproof glass,
lubricants, and explosives and as a fuel for
diesel engines.

25. Differences between animal and plant fats-
Animal fat Plant fat
1-These are relatively rich in saturated
fatty acids esp.,C16 and C18 acids.
2-These are solid at ordinary room
temperature.
3-. These have usually low Iodine
number.
4-These have usually high Reichert-
Meissl number.
5-These are stored mainly in adipose
tissues and liver(in vertebrates).
6- Oxidative rancidity is observed more
frequently.
1. These are relatively rich in unsaturated
fatty acids, esp., polyunsaturated acids.
2. These remain liquid at ordinary room
temperature.
3. These have usually high Iodine number.
4. These have usually low Reichert-Meissl
number.
5. These are stored mainly in seeds and fruits.
6. Oxidative rancidity is observed less
frequently.

26. Waxes are far less spread but equally important storage lipids. Old English word weax is
the originator of the term wax which means’ the material of the honey comb’.
Chemically these are esters of long chain saturated and unsaturated fatty acids with
long –chain monohydroxy alcohols. The fatty acids range in between C14 and C36 and the
alcohol range from C16 to C36.
Some waxes are impervious and harder than fats with higher melting point. They do
not become rancid and get less easily hydrolyzed.
7.1_Functions of waxes:-
Main functions of waxes are as follows:-
•In vertebrates, waxes are secreted by cutaneous glands as a protective coating to
keep the skin pliable, lubricated and water- proof. Wool, hair and fur are also coated
with wax.
•Birds secrete waxes to make their feather water- repellent.
•The leaves of Rhododendron, calotropis , ect., are shiny because of the deposition of
protective waxy coating . On leaf epidermis wax coating prevent water loss through
transpiration.
•Waxes are the chief storage fuel in plankton. Since marine organisms (Whale, Herring,
and Salmon) consume plankton in large quantities, waxes act as major food and
storage lipids in them.
Waxes And Functions of Waxes

27. A List of different examples of Waxes
Name of the wax Description
Sperm whale wax (spermaceti) It is composed mainly of palmitic acid esterified
with either hexacosanol CH3(CH2)24.CH2OH, or
triacontanol, CH3(CH2)28.CH2OH. This wax is also
rich in cetyl palmitate.
Bees wax It is composed mainly of palmitic acid esterified
with either hexacosanol CH3 (CH2)24.CH2OH, or
triacontanol, CH3(CH2)28.CH2OH. This wax is also
rich in myricyl palmitate.
Most of the waxes are mixtures of esters, examples are given below
Hexacosanyl palmitate Myricyl palmitate
List of different examples of Waxes:-

28. A List of different examples of Waxes
Carnauba wax It is the hardest known wax consists mainly
of fatty acids esterified with tetracosanol
CH3 (CH2)22.CH2OH and tetratriacontanol,
CH3 (CH2)34.CH2OH. It is the most important
vegetable wax and is used in the
manufacture of candles, soap, high-luster
varnishes, paints, carbon paper, batteries,
sound films, insulation, salves, ointments
and previously phonograph records.
Ambretolide It is extracted from seeds of lady’s finger.
These have characteristic odour which is
due to the presence of hydroxy acids in the
form of lactones in them.
Candelilla wax It is another vegetable wax which is softer,
contains more resin and has lower melting
point than carnauba. It is less valuable too.

29. Lipid accumulation as a survival strategy in unicellular organisms--- despite the differences in lipid composition
various organisms store lipids intracellularly. Prokaryotes do this as a response to nutrient deprivation or certain
imbalance and lipid is stored as intracytoplasmic inclusion bodies.
Following table shows the comparison of lipid accumulation from simple prokaryotes to mammals—
Lipid storage-from prokaryotes to mammals
PHAs- polyhydroxyalkanoates, PHVs- polyhydroxyvalerates , TAG- triacylglycerol, SE-sterol ester,
CE-Cholesterol esters, CIDE-cell death inducing DNA fragmentation factor-like effector, Lsd -lipid
storage droplet
Texa Lipid types
Bacteria Polymeric lipids(PHA ,PHV), TAG
(in Mycobacteria, Rhodococcus, Dietzia)
Yeast 50% triacylglycerol ;50% SE
Worms High TAG and low SE
Flies High TAG; low SE
Fish TAG and CE(in adipocytes)
Amphibia TAG and CE(in adipocytes)
Reptiles TAG and CE(in adipocytes)
Mammals TAG and CE(in adipocytes); mostly SE (in
macrophages)

30. Lipid storage :-At cellular level
•At cellular level lipid droplets (LDs) are ubiquitous dynamic organelles that store and supply lipids in
all eukaryotes and some prokaryotes cells for energy metabolism, membrane synthesis, and
production of essential lipid derived molecules.
•Lipid droplets are the dispersed phase of oil in water emulsion in the aqueous cytosol of the cells.
Their unique architecture with an interface between the dispersed oil phase and the aqueous
cytosol, specific mechanisms underlie their formation, growth and shrinkage which enable cells to
use emulsified oil when the demands for metabolic energy or membrane synthesis changes.
•The cytosol represents the continuous aqueous phase, and the dispersed oil phase, the lipid
droplets, includes neutral lipids, such as triacylglycerols, sterol esters, retinyl esters, waxes or ether
lipids, depending on the cell type and the neutral lipids they store.
•The regulation of the composition of the phospholipid surfactants at the surface of lipid droplets is
crucial for lipid droplet homeostasis and protein targeting to their surfaces.
•Cells deal with excess lipids such as fatty acids (which can act as detergents)by esterifying the
potentially toxic lipids to form more inert neutral-lipid oils, such as triacylglycerols or sterol esters.
The formation of these oils occurs within the membrane bilayers; however, because bilayers are
unsuited for storing large amounts of oil an emulsion of oil droplet forms in the cytoplasm. Specific
proteins act on cytoplasmic lipid droplets to regulate their growth and utilization in an regulated
manner.

31. Lipid storage :-At Tissue level
•Initially evolved as a facultative response to nutrient deprivation in unicellular organisms, lipid
storage in the form of triacylglycerol is primarily handled by a group of specialized cells, namely
adipocytes in vertebrates.
• Adipocytes constitute the majority of cells in the adipose tissue, an active endocrine and immune
organ that secretes a plethora of factors (adipokines) that regulate several metabolic processes
(like regulation of energy homeostasis) in distant body tissues.
•Excessive fat accumulation and adipocyte dysfunction (resultant obesity)have been linked to
various health complications such as insulin resistant, type 2 diabetes, cardiovascular diseases and
cancer.
• There are two types of fat tissue found in humans: white adipose tissue (WAT) that accumulates
lipids, and brown adipose tissue (BAT) that can burn lipids to produce heat.
•BAT is mainly found in babies, although recent studies show that adults may retain a small amount
of BAT.BAT is considered important in obesity research as it represents a potential pathway by
which the body can control metabolism by burning excess lipid to produce heat.
• Using gene expression analysis, immunophenotyping and differentiation tools, they found the
two cell types had different properties, in particular in their potential to differentiate into BAT cells,
thus indicating a different developmental pathway for the two types of fat cells..