Lipids, with carbohydrates, proteins and nucleic acids, are one of the four major classes of biologically essential organic molecules found in all living organisms; their amounts and quality in diet are able to influence cell, tissue and body physiology.

1. By Prof. Liwayway Memije-Cruz
LIPIDSLIPIDS

2.  Lipids are molecules
that contain hydrocarbons
 make up the building
blocks of the structure and
function of living cells.
 act as chemical
messengers
 serve as valuable energy
sources
 provide insulation, main
components of membranes.
 esters of glycerol and
fatty acids or as the
triglycerides of fatty acids,

3. TWO MAJOR CLASSES OF LIPIDSTWO MAJOR CLASSES OF LIPIDS
 A nonsaponifiable lipid cannot be
broken up into smaller molecules by
hydrolysis, which includes
triglycerides, waxes, phospholipids,
and sphingolipids.
 A saponifiable lipid contains one or
more ester groups allowing it to
undergo hydrolysis in the presence of
an acid, base, or enzymes.

4. Classifications of Lipids

5. MAJOR LIPID GROUPSMAJOR LIPID GROUPS
INCLUDE FATS, PHOSPHOLIPIDS, INCLUDE FATS, PHOSPHOLIPIDS,
STEROIDS, AND WAXES.​STEROIDS, AND WAXES.​

6. Fats are composed of
three fatty acids
and glycerol. These so
called triglycerides
can be solid or liquid at
room temperature.
Those that are solid are
classified as fats, while
those that are liquid are
known as oils. Fatty
acids consist of a long
chain of carbons with a
carboxyl group at one
end

7. Phospholipids

8. A phospholipid is composed of two fatty acids, a glycerol
unit, a phosphate group and a polar molecule. The phosphate
group and polar head region of the molecule is hydrophilic
(attracted to water), while the fatty acid tail is hydrophobic
(repelled by water). When placed in water, phospholipids will
orient themselves into a bilayer in which the non polar tail
region faces the inner area of the bilayer. The polar head
region faces outward and interacts with the water.
Phospholipids are a major component of cell membranes,
which enclose and protect the cytoplasm and other contents of
a cell. Phospholipids are also a major component of myelin, a
fatty substance that is important for insulating nerves and
speeding up electrical impulses in the brain. It is the high
composition of myelinated nerve fibers that causes white
matter in the brain to appear white.

9. Steroids and Waxes
Steroids have a carbon
backbone that consists of four
fused ring-like structures.
Steroids include cholesterol,
sex hormones (progesterone,
estrogen, and testosterone)
produced by gonads and
cortisone.
Waxes are composed of an
ester of a long-chain alcohol
and a fatty acid.
Many plants have leaves and
fruits with wax coatings to
help prevent water loss. Some
animals also have wax-coated
fur or feathers to repel water.
Unlike most waxes, ear wax is
composed of phospholipids and
esters of cholesterol.

10. FATS, OILS, WAXES, CERTAIN VITAMINS, HORMONESFATS, OILS, WAXES, CERTAIN VITAMINS, HORMONES
AND MOST OF THE NON-PROTEINAND MOST OF THE NON-PROTEIN MEMBRANE OF CELLS.MEMBRANE OF CELLS.

11. Lipid Soluble Vitamins
 stored in adipose tissue and in the liver.
 eliminated from the body more slowly than water-soluble vitamins.
 include vitamins A, D, E, and K. Vitamin A is important for vision
as well as skin, teeth, and bone health. Vitamin D aids in the
absorption of other nutrients including calcium and iron. Vitamin E
acts as an antioxidant and also aids in immune function. Vitamin K
aids in the blood clotting process and maintaining strong bones.

12. Organic Polymers: Biological
polymers
Biological polymers are vital to the existence of all living
organisms. In addition to lipids, other organic molecules
include:
 Carbohydrates: biomolecules that include sugars and sugar
derivatives. They not only provide energy but are also important for
energy storage.
 Proteins :composed of amino acids , proteins provide structural
support for tissues, act as chemical messengers, move muscles, and
much more.
 Nucleic acids: biological polymers composed of nucleotides and
important for gene inheritance. DNA and RNA are two types of
nucleic acids.

13. Organic Polymers

14. Soap and Detergent Chemistry

15. Water, the liquid commonly used for cleaning, has a property called surfaceWater, the liquid commonly used for cleaning, has a property called surface
tension. In the body of the water, each molecule is surrounded and attractedtension. In the body of the water, each molecule is surrounded and attracted
by other water molecules. However, at the surface, those molecules areby other water molecules. However, at the surface, those molecules are
surrounded by other water molecules only on the water side. A tension issurrounded by other water molecules only on the water side. A tension is
created as the water molecules at the surface are pulled into the body of thecreated as the water molecules at the surface are pulled into the body of the
water. This tension causes water to bead up on surfaces (glass, fabric),water. This tension causes water to bead up on surfaces (glass, fabric),
which slows wetting of the surface and inhibits the cleaning process. Youwhich slows wetting of the surface and inhibits the cleaning process. You
can see surface tension at work by placing a drop of water onto a countercan see surface tension at work by placing a drop of water onto a counter
top. The drop will hold its shape and will not spread. In the cleaningtop. The drop will hold its shape and will not spread. In the cleaning
process, surface tension must be reduced so water can spread and wetprocess, surface tension must be reduced so water can spread and wet
surfaces. Chemicals that are able to do this effectively are called surfacesurfaces. Chemicals that are able to do this effectively are called surface
active agents, or surfactants. They are said to make water "wetter."active agents, or surfactants. They are said to make water "wetter."

16. SURFACE TENSIONSURFACE TENSION
the property of the surface of a liquid that
allows it to resist an external force, due to the
cohesive nature of the water

17. SURFACE ACTIVE AGENTS, ORSURFACE ACTIVE AGENTS, OR
SURFACTANTSSURFACTANTS
Surfactants are compounds that lower the surface tension (or
interfacial tension) between two liquids, between a gas and a
liquid, or between a liquid and a solid. Surfactants may act as
detergents, wetting agents, emulsifiers, foaming agents, and
dispersants.

18. SURFACTANT TYPESSURFACTANT TYPES

19. Soaps
Soaps are water-
soluble sodium or
potassium salts of fatty
acids. Soaps are made
from fats and oils, or
their fatty acids, by
treating them
chemically with a
strong alkali.

20. The fats and oils used in soapmaking come from animal or plant sources. EachThe fats and oils used in soapmaking come from animal or plant sources. Each
fat or oil is made up of a distinctive mixture of several different triglycerides.fat or oil is made up of a distinctive mixture of several different triglycerides.
In a triglyceride molecule, three fatty acid molecules are attached to oneIn a triglyceride molecule, three fatty acid molecules are attached to one
molecule of glycerine. There are many types of triglycerides; each type consistsmolecule of glycerine. There are many types of triglycerides; each type consists
of its own particular combination of fatty acids.of its own particular combination of fatty acids.
Fatty acids are the components of fats and oils that are used in making soap.Fatty acids are the components of fats and oils that are used in making soap.
They are weak acids composed of two parts:They are weak acids composed of two parts:
A carboxylic acid group consisting of one hydrogen (H) atom, two oxygen (O)A carboxylic acid group consisting of one hydrogen (H) atom, two oxygen (O)
atoms, and one carbon (C) atom, plus a hydrocarbon chain attached to theatoms, and one carbon (C) atom, plus a hydrocarbon chain attached to the
carboxylic acid group. Generally, it is made up of a long straight chain ofcarboxylic acid group. Generally, it is made up of a long straight chain of
carbon (C) atoms each carrying two hydrogen (H)carbon (C) atoms each carrying two hydrogen (H)

21. Alkali
An alkali is a soluble salt of an alkali metal like sodium or potassium.
Originally, the alkalis used in soapmaking were obtained from the
ashes of plants, but they are now made commercially. Today, the term
alkali describes a substance that chemically is a base (the opposite of
an acid) and that reacts with and neutralizes an acid.
The common alkalis used in soapmaking are sodium hydroxide
(NaOH), also called caustic soda; and potassium hydroxide (KOH),
also called caustic potash.

22. Saponification of fats and oils is the most widely used
soapmaking process. This method involves heating fats
and oils and reacting them with a liquid alkali to produce
soap and water (neat soap) plus glycerine.

23. References:
https://www.thoughtco.com/lipids-373560
https://www.news-medical.net/life-sciences/What-are-Lipids.a
http://www.tuscany-diet.net/lipids/classification-functions/
https://byjus.com/biology/lipids/
https://www.cleaninginstitute.org/clean_living/soaps__
detergents_chemistry.aspx