Lipids - what are they? Classification. Lipid metabolism in the body and their biological role

Composition, properties and functions of lipids in the body

Nutritional value of oils and fats used in the baking and confectionery industry.

Cyclic lipids. Role in food technology and vital functions of the body.

Simple and complex lipids.

Composition, properties and functions of lipids in the body.

Lipids in raw materials and food products

Lipids combine a large number of fats and fat-like substances of plant and animal origin, which have a number of common characteristics:

a) insolubility in water (hydrophobicity and good solubility in organic solvents, gasoline, diethyl ether, chloroform, etc.);

b) the presence in their molecules of long-chain hydrocarbon radicals and esters

groupings().

Most lipids are not high molecular weight compounds and consist of several molecules linked to each other. Lipids may contain alcohols and linear chains of a number of carboxylic acids. In some cases, their individual blocks may consist of high molecular weight acids, various phosphoric acid residues, carbohydrates, nitrogenous bases and other components.

Lipids, together with proteins and carbohydrates, make up the bulk of organic substances in all living organisms, being an essential component of every cell.

When lipids are isolated from oilseed raw materials, a large group of accompanying fat-soluble substances passes into the oil: steroids, pigments, fat-soluble vitamins and some other compounds. A mixture of lipids and compounds soluble in them, extracted from natural objects, is called “crude” fat.

Main components of crude fat

Substances accompanying lipids play an important role in food technology and affect the nutritional and physiological value of the resulting food products. Vegetative parts of plants accumulate no more than 5% of lipids, mainly in seeds and fruits. For example, the lipid content in various plant products is (g/100g): sunflower 33-57, cocoa (beans) 49-57, soybeans 14-25, hemp 30-38, wheat 1.9-2.9, peanuts 54- 61, rye 2.1-2.8, flax 27-47, corn 4.8-5.9, coconut 65-72. The lipid content in them depends not only on the individual characteristics of the plants, but also on the variety, location, and growing conditions. Lipids play an important role in the vital processes of the body.

Their functions are very diverse: their role is important in energy processes, in the body’s defense reactions, in its maturation, aging, etc.

Lipids are part of all structural elements of the cell and primarily cell membranes, influencing their permeability. They are involved in the transmission of nerve impulses, provide intercellular contact, active transport of nutrients across membranes, transport of fats in the blood plasma, protein synthesis and various enzymatic processes.

According to their functions in the body, they are conventionally divided into two groups: spare and structural. Spare ones (mainly acylglycerols) have a high calorie content, are the body's energy reserve and are used by it in case of lack of nutrition and diseases.

Storage lipids are storage substances that help the body endure adverse environmental influences. Most plants (up to 90%) contain storage lipids, mainly in the seeds. They are easily extracted from fat-containing material (free lipids).

Structural lipids (primarily phospholipids) form complex complexes with proteins and carbohydrates. They are involved in a variety of complex processes occurring in the cell. By weight, they constitute a significantly smaller group of lipids (3-5% in oil seeds). These are difficult to extract “bound” lipids.

Natural fatty acids that are part of lipids in animals and plants have many common properties. They usually contain a clear number of carbon atoms and have an unbranched chain. Conventionally, fatty acids are divided into three groups: saturated, monounsaturated and polyunsaturated. Unsaturated fatty acids in animals and humans usually contain a double bond between the ninth and tenth carbon atoms; the remaining carboxylic acids that make up fats are as follows:

Most lipids have some common structural features, but a strict classification of lipids does not yet exist. One of the approaches to the classification of lipids is chemical, according to which lipids include derivatives of alcohols and higher fatty acids.

Lipid classification scheme.

Simple lipids. Simple lipids are represented by two-component substances, esters of higher fatty acids with glycerol, higher or polycyclic alcohols.

These include fats and waxes. The most important representatives of simple lipids are acylglycerides (glycerols). They make up the bulk of lipids (95-96%) and are called oils and fats. Fat contains mainly triglycerides, but also contains mono- and diacylglycerols:

The properties of specific oils are determined by the composition of the fatty acids involved in the construction of their molecules and the position occupied by the residues of these acids in the molecules of oils and fats.

Up to 300 carboxylic acids of various structures have been found in fats and oils. However, most of them are present in small quantities.

Stearic and palmitic acids are found in almost all natural oils and fats. Erucic acid is part of rapeseed oil. Most of the most common oils contain unsaturated acids containing 1-3 double bonds. Some acids in natural oils and fats tend to have a cis configuration, i.e. the substituents are distributed on one side of the double bond plane.

Acids with branched carbohydrate chains containing hydroxy, keto and other groups are usually found in small quantities in lipids. The exception is racinolic acid in castor oil. In natural plant triacylglycerols, positions 1 and 3 are preferentially occupied by saturated fatty acid residues, and position 2 is unsaturated. In animal fats the picture is the opposite.

The position of fatty acid residues in triacylglycerols significantly affects their physicochemical properties.

Acylglycerols are liquid or solid substances with low melting points and fairly high boiling points, with high viscosity, colorless and odorless, lighter than water, non-volatile.

Fats are practically insoluble in water, but form emulsions with it.

In addition to the usual physical indicators, fats are characterized by a number of physicochemical constants. These constants for each type of fat and its grade are provided by the standard.

The acid number, or acidity coefficient, shows how many free fatty acids are contained in the fat. It is expressed as the number of mg of KOH required to neutralize free fatty acids in 1 g of fat. The acid number serves as an indicator of the freshness of the fat. On average, it varies for different types of fat from 0.4 to 6.

The saponification number, or saponification coefficient, determines the total amount of acids, both free and bound in triacylglycerols, found in 1 g of fat. Fats containing residues of high molecular weight fatty acids have a lower saponification number than fats formed by low molecular weight acids.

Iodine value is an indicator of fat unsaturation. O is determined by the number of grams of iodine added to 100 g of fat. The higher the iodine value, the more unsaturated the fat is.

Waxes. Waxes are esters of higher fatty acids and high-molecular alcohols (18-30 carbon atoms). The fatty acids that make up waxes are the same as those for fats, but there are also specific ones that are characteristic only of waxes.

For example: carnauba;

cerotinic;

montanova

The general formula of waxes can be written as follows:

Waxes are widespread in nature, covering leaves, stems, and fruits of plants with a thin layer, they protect them from wetting with water, drying out, and the action of microorganisms. The wax content in grains and fruits is low.

Complex lipids. Complex lipids have multicomponent molecules, the individual parts of which are connected by chemical bonds of various types. These include phospholipids, consisting of fatty acid residues, glycerol and other polyhydric alcohols, phosphoric acid and nitrogenous bases. In the structure of glycolipids, along with polyhydric alcohols and high-molecular fatty acids, there are also carbohydrates (usually galactose, glucose, mannose residues).

There are also two groups of lipids, which include simple and complex lipids. These are diol lipids, which are simple and complex lipids of dihydric alcohols and high molecular weight fatty acids, in some cases containing phosphoric acid and nitrogenous bases.

Ormitinolipids are built from fatty acid residues, the amino acid ormitine or lysine, and in some cases including dihydric alcohols. The most important and widespread group of complex lipids are phospholipids. Their molecule is built from residues of alcohols, high-molecular fatty acids, phosphoric acid, nitrogenous bases, amino acids and some other compounds.

The general formula of phospholipids (phosphotides) is as follows:

Therefore, the phospholipid molecule has two types of groups: hydrophilic and hydrophobic.

Phosphoric acid residues and nitrogenous bases act as hydrophilic groups, and hydrocarbon radicals act as hydrophobic groups.

Scheme of the structure of phospholipids

Rice. 11. Phospholipid molecule

The hydrophilic polar head is a residue of phosphoric acid and a nitrogenous base.

Hydrophobic tails are hydrocarbon radicals.

Phospholipids are isolated as by-products during the production of oils. They are surfactants that improve the baking properties of wheat flour.

They are also used as emulsifiers in the confectionery industry and in the production of margarine products. They are an essential component of cells.

Together with proteins and carbohydrates, they participate in the construction of cell membranes and subcellular structures that perform the functions of supporting membrane structures. They promote better absorption of fats and prevent fatty liver, playing an important role in the prevention of atherosclerosis.

LIPIDS - this is a heterogeneous group of natural compounds, completely or almost completely insoluble in water, but soluble in organic solvents and in each other, yielding high molecular weight fatty acids upon hydrolysis.

In a living organism, lipids perform various functions.

Biological functions of lipids:

1) Structural

Structural lipids form complex complexes with proteins and carbohydrates, from which the membranes of cells and cellular structures are built, and participate in a variety of processes occurring in the cell.

2) Spare (energy)

Reserve lipids (mainly fats) are the body's energy reserve and participate in metabolic processes. In plants they accumulate mainly in fruits and seeds, in animals and fish - in subcutaneous fatty tissues and tissues surrounding internal organs, as well as liver, brain and nervous tissues. Their content depends on many factors (type, age, nutrition, etc.) and in some cases accounts for 95-97% of all secreted lipids.

Calorie content of carbohydrates and proteins: ~ 4 kcal/gram.

Caloric content of fat: ~ 9 kcal/gram.

The advantage of fat as an energy reserve, unlike carbohydrates, is its hydrophobicity - it is not associated with water. This ensures compactness of fat reserves - they are stored in anhydrous form, occupying a small volume. The average person's supply of pure triacylglycerols is approximately 13 kg. These reserves could be enough for 40 days of fasting under conditions of moderate physical activity. For comparison: the total glycogen reserves in the body are approximately 400 g; when fasting, this amount is not enough even for one day.

3) Protective

Subcutaneous adipose tissue protects animals from cooling, and internal organs from mechanical damage.

The formation of fat reserves in the body of humans and some animals is considered an adaptation to irregular nutrition and living in a cold environment. Animals that hibernate for a long time (bears, marmots) and are adapted to living in cold conditions (walruses, seals) have a particularly large reserve of fat. The fetus has virtually no fat and appears only before birth.

A special group in terms of their functions in a living organism are the protective lipids of plants - waxes and their derivatives, covering the surface of leaves, seeds and fruits.

4) An important component of food raw materials

Lipids are an important component of food, largely determining its nutritional value and taste. The role of lipids in various food technology processes is extremely important. Spoilage of grain and its processed products during storage (rancidity) is primarily associated with changes in its lipid complex. Lipids isolated from a number of plants and animals are the main raw materials for obtaining the most important food and technical products (vegetable oil, animal fats, including butter, margarine, glycerin, fatty acids, etc.).

2 Classification of lipids

There is no generally accepted classification of lipids.

It is most appropriate to classify lipids depending on their chemical nature, biological functions, and also in relation to certain reagents, for example, alkalis.

Based on their chemical composition, lipids are usually divided into two groups: simple and complex.

Simple lipids – esters of fatty acids and alcohols. These include fats , waxes And steroids .

Fats – esters of glycerol and higher fatty acids.

Waxes – esters of higher alcohols of the aliphatic series (with a long carbohydrate chain of 16-30 C atoms) and higher fatty acids.

Steroids – esters of polycyclic alcohols and higher fatty acids.

Complex lipids – in addition to fatty acids and alcohols, they contain other components of various chemical natures. These include phospholipids and glycolipids .

Phospholipids - these are complex lipids in which one of the alcohol groups is associated not with FA, but with phosphoric acid (phosphoric acid can be connected to an additional compound). Depending on which alcohol is included in the phospholipids, they are divided into glycerophospholipids (contain the alcohol glycerol) and sphingophospholipids (contain the alcohol sphingosine).

Glycolipids – these are complex lipids in which one of the alcohol groups is associated not with FA, but with a carbohydrate component. Depending on which carbohydrate component is part of the glycolipids, they are divided into cerebrosides (they contain a monosaccharide, disaccharide or a small neutral homooligosaccharide as a carbohydrate component) and gangliosides (they contain an acidic heterooligosaccharide as a carbohydrate component).

Sometimes into an independent group of lipids ( minor lipids ) secrete fat-soluble pigments, sterols, and fat-soluble vitamins. Some of these compounds can be classified as simple (neutral) lipids, others - complex.

According to another classification, lipids, depending on their relationship to alkalis, are divided into two large groups: saponifiable and unsaponifiable. The group of saponified lipids includes simple and complex lipids, which, when interacting with alkalis, hydrolyze to form salts of high molecular weight acids, called “soaps”. The group of unsaponifiable lipids includes compounds that are not subject to alkaline hydrolysis (sterols, fat-soluble vitamins, ethers, etc.).

According to their functions in a living organism, lipids are divided into structural, storage and protective.

Structural lipids are mainly phospholipids.

Storage lipids are mainly fats.

Protective lipids of plants - waxes and their derivatives, covering the surface of leaves, seeds and fruits, animals - fats.

FATS

The chemical name of fats is acylglycerols. These are esters of glycerol and higher fatty acids. "Acyl" means "fatty acid residue".

Depending on the number of acyl radicals, fats are divided into mono-, di- and triglycerides. If the molecule contains 1 fatty acid radical, then the fat is called MONOACYLGLYCEROL. If the molecule contains 2 fatty acid radicals, then the fat is called DIACYLGLYCEROL. In the human and animal body, TRIACYLGLYCEROLS predominate (contain three fatty acid radicals).

The three hydroxyls of glycerol can be esterified either with only one acid, such as palmitic or oleic, or with two or three different acids:

Natural fats contain mainly mixed triglycerides, including residues of various acids.

Since the alcohol in all natural fats is the same - glycerol, the differences observed between fats are due solely to the composition of fatty acids.

Over four hundred carboxylic acids of various structures have been found in fats. However, most of them are present only in small quantities.

The acids contained in natural fats are monocarboxylic acids, built from unbranched carbon chains containing an even number of carbon atoms. Acids containing an odd number of carbon atoms, having a branched carbon chain, or containing cyclic moieties are present in small quantities. The exceptions are isovaleric acid and a number of cyclic acids contained in some very rare fats.

The most common acids in fats contain 12 to 18 carbon atoms and are often called fatty acids. Many fats contain small amounts of low molecular weight acids (C 2 -C 10). Acids with more than 24 carbon atoms are present in waxes.

The glycerides of the most common fats contain significant quantities of unsaturated acids containing 1-3 double bonds: oleic, linoleic and linolenic. Arachidonic acid containing four double bonds is present in animal fats; acids with five, six or more double bonds are found in fats of fish and marine animals. Most unsaturated acids of lipids have a cis configuration, their double bonds are isolated or separated by a methylene (-CH 2 -) group.

Of all the unsaturated acids contained in natural fats, oleic acid is the most common. In many fats, oleic acid makes up more than half of the total mass of acids, and only a few fats contain less than 10%. Two other unsaturated acids - linoleic and linolenic acid - are also very widespread, although they are present in much smaller quantities than oleic acid. Linoleic and linolenic acids are found in noticeable quantities in vegetable oils; For animal organisms they are essential acids.

Of the saturated acids, palmitic acid is almost as widespread as oleic acid. It is present in all fats, with some containing 15-50% of the total acid content. Stearic and myristic acids are widely used. Stearic acid is found in large quantities (25% or more) only in the storage fats of some mammals (for example, in sheep fat) and in the fats of some tropical plants, such as cocoa butter.

It is advisable to divide the acids contained in fats into two categories: major and minor acids. The main acids of fat are acids whose content in fat exceeds 10%.

Physical properties of fats

As a rule, fats do not withstand distillation and decompose even if they are distilled under reduced pressure.

The melting point, and therefore the consistency of fats, depends on the structure of the acids that make up them. Solid fats, i.e. fats that melt at a relatively high temperature, consist predominantly of glycerides of saturated acids (stearic, palmitic), and oils that melt at a lower temperature and are thick liquids contain significant amounts of glycerides of unsaturated acids (oleic , linoleic, linolenic).

Since natural fats are complex mixtures of mixed glycerides, they do not melt at a certain temperature, but in a certain temperature range, and they are first softened. To characterize fats, it is usually used solidification temperature, which does not coincide with the melting point - it is slightly lower. Some natural fats are solids; others are liquids (oils). The solidification temperature varies widely: -27 °C for linseed oil, -18 °C for sunflower oil, 19-24 °C for cow lard and 30-38 °C for beef lard.

The solidification temperature of fat is determined by the nature of its constituent acids: the higher the content of saturated acids, the higher it is.

Fats are soluble in ether, polyhalogen derivatives, carbon disulfide, aromatic hydrocarbons (benzene, toluene) and gasoline. Solid fats are poorly soluble in petroleum ether; insoluble in cold alcohol. Fats are insoluble in water, but they can form emulsions that are stabilized in the presence of surfactants (emulsifiers) such as proteins, soaps and some sulfonic acids, mainly in a slightly alkaline environment. Milk is a natural fat emulsion stabilized by proteins.

Chemical properties of fats

Fats enter into all chemical reactions characteristic of esters, but their chemical behavior has a number of features associated with the structure of fatty acids and glycerol.

Among the chemical reactions involving fats, several types of transformations are distinguished.

Lipids, along with proteins and carbohydrates, play an important role in a living organism. The functions of lipids in a cell depend on their structure and location.

general description

Lipids are organic substances with a complex structure. They are formed by alcohols and fatty acids and are odorless and tasteless hydrophobic compounds.

Fatty acids do not have a cyclic structure of relationships between carbon atoms, they are classified as carboxylic acids and contain a carboxyl group -COOH. More than 200 types of fatty acids are found in nature. However, only 70 species were found in the human body, in the tissues of plants and animals.

Fatty acids are divided into two groups based on the presence of a double bond:

• unsaturated - contain double bonds;
• rich - do not have double bonds.

Rice. 1. Structure of fatty acids.

Fats can be of plant or animal origin, solid or in the form of liquids - oils.

Classification

All fats are divided into two main groups:

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• saponified - upon hydrolysis they form soap;
• unsaponifiable - not subject to hydrolysis.

Saponifiable lipids include simple and complex lipids. Simple lipid molecules contain only fatty acids and alcohols. Complex compounds are formed by adding an additional group, for example, a nitrogenous base.

Simple lipids are divided into two groups:

• glycerides - formed by glycerol alcohol and fatty acids;
• waxes - include higher fatty acids (contain at least 6 carbon atoms) and monohydric or dihydric alcohols.

Complex lipids include:

• phospholipids - contain lipids and phosphoric acid residues;
• Glycolipids - consist of lipids and carbohydrates.

Unsaponifiable fats are steroids. These include vital substances - sterols, bile acids, steroid hormones.

Rice. 2. Types of lipids.

Lipids form lipoproteins with proteins, which are part of various tissues of animals and plants. Blood plasma lipoproteins have been well studied. They are also present in milk, yolk, and are part of chloroplasts and plasmalemma.

Meaning

Lipids are involved in the metabolism and construction of the body, provide energy and regulate growth. A list of common functions of lipids and their descriptions are presented in the table.

Rice. 3. Structure of the plasmalemma.

In humans and higher vertebrates, fat is accumulated by special cells - adipocytes, which form adipose tissue.

What have we learned?

From the biology lesson we learned what function lipids perform in the cell membrane and in the body as a whole. Lipids are complex substances consisting of alcohols and fatty acids. Various modifications of fats allow lipids to participate in various activities of the body. Lipids are part of hormones, plasmalemma, vitamins, they can accumulate in fatty tissues and serve as a source of energy, water, and protect against damage and cold.

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I. LIPIDS - organic substances characteristic of living organisms, insoluble in water, but soluble in organic solvents (carbon disulfide, chloroform, ether, benzene), giving hydrolysis of high molecular weight fatty acids. Unlike proteins, nucleic acids and polysaccharides, they are not high-molecular compounds, their structure is very diverse, they have only one common feature - hydrophobicity.

Lipids perform the following functions in the body:

1. energy - are reserve compounds, the main form of energy and carbon storage. The oxidation of 1 g of neutral fats (triacylglycerols) releases about 38 kJ of energy;

2. regulatory– lipids are fat-soluble vitamins and derivatives of some fatty acids that are involved in metabolism.

3. structural - are the main structural components of cell membranes, form double layers of polar lipids into which enzyme proteins are embedded;

4. protective function:

Ø protects organs from mechanical damage;

Ø participates in thermoregulation.

The formation of fat reserves in the body of humans and some animals is considered an adaptation to irregular nutrition and living in a cold environment. Animals that hibernate for a long time (bears, marmots) and are adapted to living in cold conditions (walruses, seals) have a particularly large reserve of fat. The fetus has virtually no fat and appears only before birth.

Based on their structure, lipids can be divided into three groups:

Ø simple lipids - these include only esters of fatty acids and alcohols. These include: fats, waxes and steroids;

Ø complex lipids - they contain fatty acids, alcohols and other components of various chemical structures. These include phospholipids, glycolipids, etc.;

Ø Lipid derivatives are mainly fat-soluble vitamins and their precursors.

In animal tissues, fats are in a partially free state; to a greater extent they form a complex with proteins.

According to the chemical composition, structure and function performed in a living cell, lipids are divided into:

II. Simple lipids are compounds consisting only of fatty acids and alcohols. They are divided into neutraol acylglycerides (fats) and waxes.

Fats– reserve substances that accumulate in very large quantities in the seeds and fruits of many plants are part of the human body, animals, microbes and even viruses.

According to the chemical structure, fats are a mixture of esters (glycerinodes) of the triatomic alcohol glycerol and high molecular weight fatty acids - built according to the type:

CH 2 -O-C-R 1

CH 2 -O-C-R 3

where R1, R2, R3 are radicals of high molecular weight fatty acids.

Fatty acids are long-chain monocarboxylic acids (containing 12 to 20 carbon atoms).

Fatty acids that make up fats are divided into saturated (do not contain double carbon-carbon bonds) and unsaturated or unsaturated (contain one or more double carbon-carbon bonds). Unsaturated fatty acids are divided into:

1. monounsaturated – contain one bond:

2. polyunsaturated – contain more than one bond.

Of the saturated acids, the most important are:

palmitic (CH 3 – (CH 2) 14 – COOH)

stearic (CH 3 – (CH 2) 16 – COOH);

The most important of the unsaturated fatty acids are oleic, linoleic and linolenic.

CH 3 – (CH 2) 7 – CH = CH– (CH 2) 7 – COOH – oleic acid

CH 3 – (CH 2) 4 – CH = CH – CH 2 – CH = CH – (CH 2) 7 – COOH – linoleic acid

CH 3 –CH 2 –CH=CH–CH 2 –CH=CH–CH 2 –CH=CH–(CH 2) 7 – COOH – linolenic

The properties of fats are determined by the qualitative composition of fatty acids, their quantitative ratio, the percentage of free fatty acids not bound to glycerol, etc.

If the fat composition is dominated by saturated (marginal) fatty acids, then the fat has a solid consistency. On the contrary, unsaturated (unsaturated) acids predominate in liquid fats. Liquid fats are called oils.

An indicator of the saturation of fat is the iodine number - the number of milligrams of iodine that can join 100 g of fat at the site where the double bonds in the molecules of non-ideal acids are broken. The more double bonds in a fat molecule (the higher its unsaturation), the higher its iodine number.

Another important indicator is the saponification number of fat. When fat is hydrolyzed, glycerol and fatty acids are formed. The latter form layers with alkalis called soaps, and the process of their formation is called saponification of fats.

The saponification number is the amount of KOH (mg) used to neutralize the acids formed during the hydrolysis of 1 g of fat.

A feature of fats is their ability to form aqueous emulsions under certain conditions, which is important for nourishing the body. An example of such an emulsion is milk, the secretion of the mammary glands of mammals and humans. Milk is a thin emulsion of milk fat in its plasma. 1 mm 3 of milk contains up to 5-6 million milk fat globules with a diameter of about 3 microns. Milk lipids consist predominantly of triglycerides, in which oleic and palmetic acids predominate.

Polyunsaturated fatty acids (oleic, linoleic, linolenic and arachidonic acids) are called irreplaceable (essential), because they are necessary for man. Polyunsaturated fatty acids promote the release of cholesterol from the body, preventing and weakening atherosclerosis, and increase the elasticity of blood vessels.

Due to the fact that unsaturated fatty acids have double bonds, they are very easily oxidized. The process of fat oxidation can occur on its own due to the addition of atmospheric oxygen at the site of double bonds, but it can be significantly accelerated under the influence of the enzyme lipoxygenase.

Waxes– esters of high molecular weight fatty acids and monohydric alcohols with a long carbon chain. These are solid compounds with pronounced hydrophobic properties. Fatty acids contain from 24 to 30 carbon atoms, and high-molecular alcohols contain 16-30 carbon atoms.

R 1 – CH 2 – O – CO – R 2

The main function of natural waxes is the formation of protective coatings on the leaves, stems and fruits of plants, which protect the fruits from drying out and damage by microorganisms. Honey is stored under a beeswax cover and bee larvae develop. Lanolin is a wax of animal origin that protects hair and skin from water.

Steroids– esters of cyclic alcohols (sterols) and higher fatty acids. They form the saponified fraction of lipids.

The saponified fraction of lipids is formed by sterols.

II . Complex lipids

Phosphatides (phospholipids) - fats containing phosphoric acid associated with a nitrogenous base or other compound ( IN).

CH 2 -O-C-R 1

CH 2 -O- P = O

If IN is a choline residue, the phosphatide is called lecithin; if colamine - cofaline. Lecithin predominates in grains and seeds; cephalin accompanies it in small quantities.

- (from Greek lipos - fat * a. lipids; n. Lipide; f. lipides; i. lipidos) - group of biochemicals. components of living matter, insoluble in water, but soluble in organic matter. solvents; potential precursors of petroleum hydrocarbons. K... Mountain encyclopedia