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ANIMAL BIOCHEMISTRY
Presented by:Hina Amir
Functions of Lipids
FUNCTIONS OF LIPIDS
ENERGY
INDUSTRY
IMMUNITY SIGNALING
VITAMI
N MEMBRANESLIPID
S
Lipids form excellent energy storage molecules
As lipid deposits in stroma of the chloroplast
Carry 9 kilocalories of energy as opposed to
4 kilocalories that carbohydrates
Waxes stored in plankton as biofuel
Adipose tissue of vertebrates.
Fats in seeds
1. Energy storage
Lipids or Glucose for Energy?
H3CCH2
CH2
CH2
CH2
CH2
CH2
CH2
CH2
CH2
CH2
CH2
CH2
CH2
CH2
CH2
CH2
CO
OH
HC
CH
HC
CH
CH
CH2OH
O
HO
HO
OH
HO More reduced state (more H bound to C) More potential for oxidation
Less reduced state (more O bound to C) Less potential for oxidation
2. Thermal insulation
Fat conducts heat slowly and therefore the triglycerides, which are stored as fat in vertebrates, are important for maintainingoptimum temperature.
It help in conserving energy of organisms undergoing hibernation.
Mechanical protection Adipose tissue act as physical cushion in the palms of the hands, soles of the feet, and around the eyes kidneys.
Waterproofing The waxy cuticle on the leaf epidermis or
as oils on birds’ feathers.
Buoyancy
Since fat is less dense than water, fat reserves provide buoyancy for
aquatic animals.
In the liver cholesterol is the precursor of the bile acids, 24 steroid carboxylic acids that aid in the digestion of foods, especially lipids, and, when linked with the amino acids glycine or taurine, form the bile salts
As digestive enzyme
Platelet-activating factor (PAF) is a potent mediator that occurs at very low concentrations in cells and tissues
Immune response
Dipalmitoyl lecithin:surfactant
.
Absence of it causes respiratory distress.
As surfactant
Phosphatidylethanolamine in addition to phosphatidylserine (found in most tissues) are also found in cell membranes.
Phosphatidylserine also plays a role in apoptosis (programmed cell death).
Apoptosis
While studying sleep inducing substances researchers point out that certain lipids or lipids derivatives are involved in sleep induction ;
Prostaglandin
in rodents, primates, and most probably in humans as well
Sleep Induction
Liposomes when combined with tissue-specific antibodies function as carriers of drugs in the circulation, targeted to specific organs, e.g. in cancer therapy.
Plant-derived isoprenoid compounds include rubber, camphor (used in several cough preparations)
: Isoprene unit.
Medicine
Arachidonic acid is the eicosanoid precursor
Eicosanoids are three groups of structurally related compounds
Prostaglandins
Leukotrienes
Thromboxanes
Biological functions:
COO-
arachadonic acid
Biological Processes Regulated by Eicosanoids
1. Blood clotting(prostaglandin)2. dilates blood vessels
3. inhibits platelet aggregation4. Inflammatory response
•Lipid rafts are plasma membrane microdomains rich in cholesterol and sphingolipids.
•important for neuronal cell adhesion, axon guidance and synaptic transmission.
•crucial for neural development and function.
Neural functioning
Insect cuticle waterproof and prevent from desication
Stress Tolerance in Cyanobacteria In plants the leaves are covered by waxy cuticles,
which prevent excess water loss or entry. Carnuba, from Brasilian wax palm In animals, such as ducks, oil is found on their feathers
to ensure excess water is not absorbed. In vertebrates, a waxy layer is found on their skin and
fur. Some bees are able to synthesise their own wax, which
is used to construct a honeycomb. Beeswax
Structural support
Lauric acid is a medium chain fatty acid antiviral, antibacterial, and antiprotozoal. destroy lipid-coated viruses such as HIV,
herpes, influenza, pathogenic bacteria.
Coconut oil.
Function as antibacterial
Cholesterol is vital in
producing vitamin D and
some hormones
Gibberellins – plant growth
substances e.g. carotenes,
photosynthetic pigments,
coloration pigments, steroid
hormone.
Precursor
While plant oils such as cotton, coconut, palm, castor beans, soy, and sunflowers are also natural sources of stearic acid,
Soap making. deodorants foundation creams, hand lotions, hair straightening products, and shaving creams.
Cosmetic industryFatty acids are the
main com
ponent of
soap, where their
tails are
soluble in oily dirt
and their heads are
soluble in water to
emulsify
and wash aw
ay the
oily dirt.
Numerous plant oils, or lipids, go into making natural insecticides.
Catnip oil repels mosquitoes by irritating them,
canola oil controls a variety of insects.
Citronella oil is used in candles, lotions, sprays and wipes to repel insects.
Citrus oils, pine oil and mint oil also are used to produce insecticides.
In pesticides
Biodiesel is a clean-burning fuel produced from plant lipids such as soybean oil and will be a good source of feul in near future.
Lubricantspalm, sunflower, soybean oils are used to make industrial bio-lubricants. engine oil, grease and metalworking fluids.
Fuel + lubricant
CONCLUSION
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