Lipid functions

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