Simple lipids,

complex lipids

and dietary

lipids.

Lipids or Fats

The Lipids are water-insoluble organic biomolecules that can be

extracted from the cells or the tissues by means of non-polar

solvents (chloroform, ether or benzene).

There are several families or classes, but all derive their

characteristic properties of the hydrocarbon of a large part of their

structure.

They are structural components of biologicalmembranes.

BIOLOGICAL FEATURES

Constitute forms of storage and transport of moleculesrich in energy.

They serve as a protective coating on the surface ofmany organisms.

Are components of the cell surface involved in therecognition of the specificity of species and tissueimmunity.

Some substances of lipids have a significant biologicalactivity (vitamins and hormones).

CLASSIFICATION

LIPIDS

Based on the structure of their skeleton

SIMPLE COMPLEX

TERPENES

STEROIDS

PROSTAGLANDINS

ACILGLYCEROL

PHOSPHOGLYCERIDES

SPHINGOLIPIDS

WAXES

Saponificable beacuse they formsoaps in response to alkalinehydrolysis

Not saponificable because theydon’t contain fatty acids

Lipids are often found in combined form

GLYCOLIPIDS LIPOPROTEIN

CLASSIFICATION

COMPLEXLIPIDS

ACYLGLYCEROLS PHOSPHOGLYCERID SPHINGOLIPIDS

Contain fatty acids therefore they are saponifiable

They differ in the structure of the molecule to which the fatty acids

are attached with covalent bonds.

WAXES

FATTY ACIDS

All have a long hydrocarbon chain that may be:

Saturated fatty acids and

unsaturated hydrocarbons

have very different

conformations. Typically

the saturated queues have

more flexible because each

link has a complete

freedom of rotation.

Saturatedfatty acids

Palmitic acid

Unsaturatedfatty acids

Oleic acid

ESSENTIAL FATTY ACIDS

They are defined essential fatty acids and are indispensable in the

mammal’s diet because its cannot be synthesized from other

precursors.

Linoleic acid

CH3 CH(CH2)4 CH CH2 CH CH COOH(CH2)7

a-linolenic acid

CH3 CHCH2 CH CH2 CH CH COOH(CH2)7CH CH2 CH

ACYLGLYCEROLS o TRIGLYCERIDES

Are esters of fatty acids and of an alcohol to three

carbon atoms

C

C

C

H2 O H

H2 O H

H O H

Glycerolo

C C C C C

C C C C C

C C C C C

Fatty acids

Can be:

MONOGLYCERIDES

DIGLYCERIDES

TRIGLYCERIDES

THE MAJOR PROPERTIES

- At room temperature can be:

“SOLIDS” and are alsocalled “FAT”

“LIQUIDS” and are alsocalled “OIL”

- They can be defined:

“SIMPLE” If the fatty acids are the same

“MIXED”

If the fatty acids are different

Are the major components of storage lipids in

animal cells

PHOSPHOGLYCERIDES o PHOSPHOLIPIDS

- Are amphipathic moleculesglicerolo

acido fosforico

Acidi grassi

-They are characteristiccomponents and the main cellmembranes.

-They distinguish between thePLASMOGEN since they have ahydroxyl esterified by a fatty acidand an esterified by an aliphaticchain. They are particularly abundantin the membranes of muscle andnerve cells

SPHINGOLIPIDS

Fatty acid

Group polar

Sphingosine

-They are present in highamounts in the brain andnervous tissue and only intraces in the fatty deposits.

WAXES

Solids are esters of higher fatty acids with long-chainfatty alcohol or sterols. They are not soluble in water.

They are soft and pliable but hard to warm cold.

The waxes are protective coatings on skin, hair and fins,on the leaves and fruits of plants and sull'esoscheletro ofmany insects.

An example……

Beeswax has as main components esters of palmitic acid with fatty

alcohol, long chain (26 to 36 C atoms).

SIMPLE LIPIDS

TERPENES STEROIDS PROSTAGLANDINS

They don’t contain fatty acids are therefore not saponificable

In cells and tissues are present in minor amount with rispectto the complex lipids

It contains many biologically active substances: vitamins –hormones - soluble molecules highly specialized

TERPENES

CH2

C

CH

CH2

CH3ISOPRENE

The terpenes are composed of multiple hydrocarbonto 5 C atoms, isoprene.

The isoprene units may be arranged spin or tail-to-tail.

The terpenes can be linear or cyclic and some contain structures of both types.

An example…

Carotenoidi

STEROIDS

Steroids are derived from a saturated hydrocarbon tetracyclic.

STERANE

19

18

A B

C D

- All steroids are derived from SQUALENE that cyclizes easily.

Since this compound is derived CHOLESTEROL.

PROSTAGLANDINS

Prostaglandins are a family offatty acid derivatives that have avariety of biological activity ofthe hormonal type or regulator.

A bit 'of history ...... in 1930were found in seminal plasma, inprostate and seminal vesicles verysmall amounts of substances thatlowered blood pressure andstimulated contraction of somesmooth muscles.

All derive from the cyclization offatty acids at 20 C atoms(arachidonic acid) which isformed by the acid essentialfatty acid linoleic acid.

INTAKE OF NUTRIENTS

FOOD(macro e micro-nutrients)

NUTRITIONALSTATUS

HEALTHSTATUS

ABSORPTIONNUTRIENT

UTILIZATION AT THE CELLULAR LEVEL

DIETARY LIPIDS

DIETARY LIPIDS

The lipids that are of greater importance from a nutritional point of view are:

THE MAIN FUNCTION

Energy supply 9Kcal/g.

Act as an energy reserve in the adipose tissue.

Provide essential fatty acids (linoleic acid and linolenic acid) for thesynthesis of biologically active molecules (prostaglandins,leukotrienes, thromboxanes).

Forniscono colesterolo.

FATTY ACIDS TRIGLYCERIDES CHOLESTEROL PHOSPHOLIPIDS

Trasport of fat-soluble vitamins (vit.A, vit.D, vit.E, vit.K, carotenoids).

Lipids di animal origin

eggs

fish

Oils and animal fats arecontained in tissues ofdifferent animals, fish,milk and derivatives andmammalian eggs.

meat

cheese

MAIN SOURCES OF DIETARY FOOD

Lipids of vegetable origin

Oils and fats of vegetable origin derived from seeds(peanut, sunflower, corn, soybean, canola, grapeseed,sesame ... ..) or fruit (olive, palm).

Olive oil.

Peanut oil, sunflower, corn, soybean.

Nutrient composition of extra virgin olive oil

MINOR COMPONENTS– 0.5%-1%

FATS – 99%

Phenols - tocopherols - Sterols - Carbon compounds - Aromatic compounds - alcohols - Colour pigments - Waxes - Fat-soluble vitamins

TRIGLYCERIDES

C

C

C

H2 O H

H2 O H

H O H

C C C C C

C C C C C

C C C C C

Glycerol Fatty acid

EXTRA VIRGIN OLIVE OIL

(g su 100 g of edible part)

Fatty acids composition

margarinebutter

OLEIC acid 73.6

LINOLEIC acid(w6) 7.85LINOLENIC acid (w3) 0.99

PALMITIC acid 10.64STEARIC acid 3.06

OLEIC acid 32.05

LINOLEIC acid (w6) 16.62LINOLENIC acid (w3) 1.02

PALMITIC acid 19.32STEARIC acid 5.53

OLEIC acid 20.7

LINOLEIC acid (w6) 1.57LINOLENIC acid (w3) 1.18

PALMITIC acid 20.8STEARIC acid 9.40

Extra virgin oliveoil