Module 10: : Lipids

lipins, lipoids or lipides

Lipids are otherwise known as

Lipids

They compose a group of fat – like substances consisting of fatty acids, their naturally occurring compounds and substances found naturally in chemical association with them.

Lipids

They are usually found in animal and plant tissues

ENERGY SOURCE

When oxidized, each gram of fat releases 9 kcal of energy, or more than twice the energy released by oxidation of a gram of carbohydrate

ENERGY STORAGE

Most of the energy stored in the body is in the form of lipids (triglycerides) that are deposited in fat cells called the adipocytes

CELL MEMBRANE STRUCTURAL COMPONENTS

Phospholipids make up the basic structure of all cell membranes

HORMONES

The steroid hormones are critical chemical messengers that allow tissues of the body to communicate with one another

VITAMINS

The lipid soluble vitamins (Vitamins A, D, E & K) play a major role in the regulation of several biological processes

PROTECTION

Fats serve as shock absorbers or as protective layers for most vital organs

INSULATION

Fat stored beneath the skin (subcutaneous fat) serves to insulate the body from extremes of cold temperature

DERIVED LIPIDS

substances derived from the hydrolysis or the breaking down of simple or compound lipid molecules

FATTY ACIDS

are long chain monocarboxylic acids that can be classified according to the following basis

Aliphatic fatty acids

- fatty acids whose atoms are connected to each other in an open – ended chain-like structure

Saturated fatty acids

fatty acids that are oriented with single sigma bonds only that correspond to the general formula CH3(CH2)nCOOH

CH3(CH2)nCOOH

General formula of saturated fatty acids

Unsaturated fatty acids

fatty acids that contain one or more double bonds in its molecular structure

Essential fatty acids

unsaturated fatty acids which are necessary for specific biochemical functions but cannot be synthesized by the body

Linoleic acid

required for the biosynthesis of arachidonic acid that serves as the precursor substance of an important group of hormones known as the Eicosanoids

Alicyclic fatty acids

fatty acids whose atoms are connected to each other in an enclosed polygon or ring-like structure

Chaulmoogric acid

a medically significant fatty acid used for the preparation of ethyl chaulmoograte which is used for the treatment of leprosy

Volatile fatty acids

contain 10 or less carbon atoms

Volatile fatty acids

They are water – soluble but this solubility decreases as the number of carbon atoms increases.

Non – volatile fatty acids

are insoluble in water and HCl; slightly soluble in alcohol but soluble in chloroform, ether and carbon tetrachloride

Non – volatile fatty acids

Their solubility in NaOH is due to the formation of soap (saponification).

GLYCEROL

it is a trihydric alcohol otherwise known as glycerin; trihydroxypropane or 1,2,3 – propanetriol

GLYCEROL

The main alcoholic component of triglycerides

GLYCEROL

GLYCEROL - can be prepared from saponification, fermentation and the synthesis of propylene

STEROLS

hydroxyl derivatives or alcohols with the cyclopentanoperhydrophenantrene structure

STEROLS

alcoholic component of the steroids

SPHINGOSINE

a long-chain nitrogen containing alcohol or an amino glycol that serves as the alcoholic component of compound lipids usually found in the nerve tissues like gangliosides, sphingomyelins and cerebrosides

C18H37O2N

Molecular Formula of Sphingosine

NITROGENOUS BASES

nitrogen containing compounds that serve as structural components of some compound lipids

CHOLINE

a soluble ammonia derivative (amine) that is found in animal and plant tissue and helps to prevent fat from being deposited in the liver

C5H15NO2

Molecular Formula of Choline

ETHANOLAMINE

a colorless, moderately viscous liquid with an ammoniacal odor contained in cephalins and phospholipids derived metabolically from the decarboxylation of the amino acid serine

SIMPLE LIPIDS

esters formed from the esterification reaction between various alcohols and the fatty acids

TRIGLYCERIDES

triesters formed from the esterification reaction between glycerol and 3 fatty acid molecules otherwise known as the triacylglycerols or the neutral fats

TRIGLYCERIDES

the usual storage form of lipids found in a living human body

TRIGLYCERIDES

collective term for fats and oils

SIMPLE TRIGLYCERIDES

triesters formed from the esterification reaction between glycerol and 3 identical fatty acid molecules

MIXED TRIGLYCERIDES

triesters formed from the esterification reaction between glycerol and 3 fatty acid molecules that are different from one another

WAXES

esters of long chain fatty acids with long chain alcohols, thus have a higher molecular weight than fats and oils

WAXES

They are denser than fats and oils and are completely insoluble in water

BEESWAX

wax formed from the honeycomb of bees that are commercially processed for use in furniture polishes, varnishes, candles, and crayons

myricyl palmitate

chemical name of beeswax

SPERMACETI WAX

a white waxy solid obtained from the oil in the head of sperm whales and other cetaceans (dolphins) used in cosmetics, candles, and ointments

chemical name of spermaceti wax

cetyl palmitate

CARNAUBA WAX

wax obtained from the cuticle of the young leaves of the carnauba tree used in the manufacture of polishes and candles

myricyl cerotate

chemical name of carnauba wax

LANOLIN

wax extracted from sheeps wool that serves as a protective coating of the hair and skin, thus often used as a base in ointments, skin creams and other dermal medications

LANOLIN

It is also known as wool wax

CHINESE WAX

a white or yellowish crystalline wax extracted from the seeds and the cuticle of the young leaves of the Chinese tree or the tung tree, used in paints and varnishes to speed up drying, and also as a waterproofing agent

CHINESE WAX

It is also known as tung wax

CHOLESTERYL ESTERS

esters of cholesterol formed in the blood plasma that serve as protective agents on the surfaces of some vital organs like the liver, spleen and kidneys

COMPOUND LIPIDS

esters of fatty acids with alcohol but containing other chemical groups in addition to alcohol also known as complex lipids

PHOSPHOLIPIDS

are substituted fats containing phosphoric acid and nitrogen otherwise known as phosphorized fats; phospholipins or phosphatides

PHOSPHOLIPIDS

generally composed of an alcohol, fatty acids, phosphoric acid and a nitrogenous base

PHOSPHOLIPIDS

they are the fatty matter of the active tissues in the body and are used to transport fat to the different tissues.

GLYCOLIPIDS

compounds of fatty acids that has a carbohydrate group

GLYCOLIPIDS

these substances are found mainly in the cell membranes of nerve and brain tissues

CEREBROSIDES

glycolipids containing sphingosine, fatty acids and a monosaccharide group in the form of D glucose or D galactose in each of its molecule

CEREBROSIDES

serve as important constituents of the medullary sheath of nerves in brain tissues particularly in the white matter of the brain; also of the spleen, kidneys, liver, blood corpuscles, lungs, adrenals and retina of the eye examples are: galactocerebroside; glucocerebroside; phrenosin; cerebrone; nervone; oxynervone

GANGLIOSIDES

glycolipids containing sphingosine; fatty acids, neuraminic acid and a complex oligosaccharide molecule

GANGLIOSIDES

serve as important constituents of the ganglion cells of the Central Nervous System that aid in its normal functioning

PHOSPHATIDIC ACIDS

compounds similar to phospholipids in structure but with no nitrogenous base

PHOSPHATIDIC ACIDS

serve as important constituents in some plant tissues and in the heart tissues (cardiolipins) of human beings and animals

Cerebrosulfatide

a sulfolipid containing sulfuric acid, phosphoric acid, glycerol, aminoethyl alcohol and a fatty acid that is found in the brain tissue.

SULFOLIPIDS

lipids containing Sulfuric acid

LIPOPROTEINS

molecules that consist of a core of hydrophobic lipids bonded to hydrophilic protein molecules that serve as carrier molecules for the transport and absorption of other lipid molecules, primarily cholesterol

LIPOPROTEINS

occur in the cytoplasm, plastids, membranes and mitochondria of living cells

CHYLOMICRONS

lipoproteins that have a density less than 0.95 g/ml

VERY LOW DENSITY LIPOPROTEIN (VLDL)

lipoproteins that have a density from 0.98 to 1.019 g/ml

LOW DENSITY LIPOPROTEIN (LDL)

lipoproteins that have a density from 1.019 to 1.063 g/ml

HIGH DENSITY LIPOPROTEIN (HDL)

lipoproteins that have a density from 1.063 to 1.210 g/ml

MISCELLANEOUS LIPIDS

substances associated with lipids in nature

CHOLESTEROL

a lipid constituent of all animal cells

CHOLESTEROL

It is also present in nervous tissues

STEROIDS

A large group of organic fat – soluble compounds distinguished by the presence of the steroid ring or the cyclopentanoperhydrophenantrene structure, with a great diversity of physiological activity.

7 DEHYDROCHOLESTEROL

a sterol derived from cholesterol found richly in the stratum granulosum of the epidermis of the human skin

7 DEHYDROCHOLESTEROL

Upon exposure to the sun, it is converted to cholecalciferol (vitamin D1) by the action of the ultraviolet radiation coming from the sun

ERGOSTEROL

a sterol that usually occurs in some plants, yeast, certain mushrooms and mainly in ergot, a fungus of rye

ERGOSTEROL

It is also absorbed in the stratum granulosum of the human skin and is converted into ergocalciferol (vitamin D2) once exposed to the ultraviolet radiation coming from the sun

ADRENOCORTICOSTEROIDS

group of hormones produced mainly in the adrenal cortex that help regulate metabolism, resistance to stress and salt & water balance

HYDROCORTISONE

steroid hormone used in response to tissue damage causing inflammation

ALDOSTERONE

steroid hormone that controls the balance of salt and water in the human body

SEX HORMONES

group of hormones produced in the sex organs and the adrenal gland that help in the normal functioning and the development of the sexual characteristics of human beings

PROGESTERONE

steroid hormone produced in women, first by the corpus luteum of the ovary to prepare the womb for the fertilized ovum, and later by the placenta to maintain pregnancy

ESTROGEN

steroid hormone produced mainly in the ovaries that stimulate estrus and the development of female secondary sexual characteristics

TESTOSTERONE

a male steroid hormone produced in the testicles and responsible for the development of male secondary sexual characteristics

VITAMIN D (Calciferol)

a lipid soluble vitamin needed to ensure the formation and maintenance of healthy bones and teeth

Calciferol

other name for Vitamin D

BILE ACIDS AND SALTS

steroids derived from bile needed for the emulsification, digestion and absorption of dietary lipids

PROSTAGLANDIN

an unsaturated fatty acid found in all mammals that resembles hormones in its activity

LEUKOTRIENE

a substance that functions as a powerful but short-range chemical messenger in various body systems, including the circulatory, nervous, and immune systems

LEUKOTRIENE

It helps regulate the state of blood vessels and airways, and influence the activities of certain white blood cells

THROMBOXANE

a substance formed in the platelets that causes blood clotting and constriction of blood vessels

LIPID SOLUBLE VITAMINS

organic substances essential in small quantities to the nutrition and normal metabolism of most animals

LIPID SOLUBLE VITAMINS

They are insoluble to water but soluble in fat solvents like ethyl alcohol, carbon tetrachloride, chloroform and petroleum ether

VITAMIN A (Retinol)

a fat-soluble vitamin found in green and yellow vegetables and animal products such as egg yolk and milk

Vitamin A

is important to the health of the outer layer of cells in the skin and organs