1. Lipids
Compiled by group 5
Imanuelle Orchidea
Meiliza Ekayanti
Teguh Permana

3. overview
• Lipids are diverse in form and are defined by
solubility in non-polar solvents (and insolubility in
water)
• Lipids are used for efficient energy storage, as
structural components of cell membranes, as
chemical messengers and as fat-soluble vitamins
with a variety of functions
• Our cells can also biosynthesize most lipids

5. Types of Lipids
 Following is a summary of the types of lipids we will
study and their general structures:

6. Fatty Acids
The simplest lipids are the fatty acids, which rarely exist alone in
nature, but instead are usually a component of more complex
lipids
Fatty acids are carboxylic acids with a long hydrocarbon chain
attached
Although the acid end is polar, the nonpolar hydrocarbon tail
makes fatty acids insoluble (or sparingly soluble) in water
Fatty acids can be classified by how many double bonds are
present in the hydrocarbon tail:
- Saturated fatty acids have only single bonds
- Monounsaturated fatty acids have one double bond
- Polyunsaturated fatty acids have two or more double
bonds

8. • Lipids may be broadly defined as
hydrophobic or amphipathic small
molecules that originate entirely or in
part by carbanion-based condensations of
thioesters and/or by carbocation-based
condensations of isoprene units

9. Building Blocks

11. Structures and Melting Points of Saturated Fatty Acids

13. Physical Properties of Saturated Fatty
Acids
Saturated fatty acids have:
• Molecules that fit closely
together in a regular pattern
• Strong attractions
(dispersion forces) between
fatty acid chains
• High melting points that
makes them solids at room
temperature.

14. Structures and Melting Points of Unsaturated Fatty Acids

15. Physical Properties of Unsaturated Fatty Acids
Unsaturated fatty acids have:
• Nonlinear chains that do not allow molecules to pack closely
• Weak attractions (dispersion forces) between fatty acid chains
• Low melting points and so are liquids at room
temperature

16. Triglycerides
• The triesters of fatty acids with glycerol (1,2,3trihydroxypropane) compose the class of lipids
known as fats and oils.
• These triglycerides (or triacylglycerols) are found
in both plants and animals, and compose one of
the major food groups of our diet.
• Triglycerides that are solid or semisolid at room
temperature are classified as fats, and occur
predominantly in animals.
• Those triglycerides that are liquid are called oils
and originate chiefly in plants, although
triglycerides from fish are also largely oils.

17. Fats and Oils
Formed from glycerol and fatty acids
O
CH2
OH
CH
OH
HO
+
C
O
(C H 2 ) 1 4 C H 3
HO
C
(C H 2 ) 1 4 C H 3
O
CH2
OH
g lyc e ro l
HO
C
(C H 2 ) 1 4 C H 3
p a lm itic a c id (a fa tty a c id )
17

18. Triglycerides (triacylglcerols)
Esters of glycerol and fatty acids
e ste r b o n d s
O
CH2
O
C
(C H 2 ) 1 4 C H 3
+
H 2O
(C H 2 ) 1 4 C H 3
+
H 2O
+
H 2O
O
CH
O
C
O
CH2
O
C
(C H 2 ) 1 4 C H 3
18

19. Non-fatty Acid Lipids
• Non-fatty acid lipids are steroids group
• Contains steroid chain structure
• The most familiar lipid with steroid chain is
cholesterol
• Cholesterols are biosynthesized naturally
in our bodies

20. Cholesterol Biosynthesis
Conversion of 3-hydroxy-3-methyl-glutaryl-Coenzyme A to
mevalonate by HMG CoA reductase. This is the rate limiting
step in cholesterol biosynthesis.

22. Trivial Names of Fatty Acids
• Trivial names (or common names) are
non-systematic historical names, which
are the most frequent naming system used
in literature. Most common fatty acids
have trivial names in addition to their
systematic names (see below). These
names frequently do not follow any
pattern, but they are concise and often
unambiguous.

23. Saturated
Formula
Common Name
Melting Point
CH3(CH2)10CO2H
lauric acid
45 ºC
CH3(CH2)12CO2H
myristic acid
55 ºC
CH3(CH2)14CO2H
palmitic acid
63 ºC
CH3(CH2)16CO2H
stearic acid
69 ºC
CH3(CH2)18CO2H
arachidic acid
76 ºC

24. Unsaturated
Formula
Common Name
Melting Point
CH3(CH2)5CH=CH(CH2)7CO2H
palmitoleic acid
0 ºC
CH3(CH2)7CH=CH(CH2)7CO2H
oleic acid
13 ºC
CH3(CH2)4CH=CHCH2CH=CH(CH2)7CO2H
linoleic acid
-5 ºC
CH3CH2CH=CHCH2CH=CHCH2CH=CH(CH2)7CO2H
linolenic acid
-11 ºC
CH3(CH2)4(CH=CHCH2)4(CH2)2CO2H
arachidonic acid
-49 ºC

25. Systematic names
• Systematic names (or IUPAC names) derive
from the standard IUPAC Rules for the
Nomenclature of Organic Chemistry, published in
1979,[6] along with a recommendation published
specifically for lipids in 1977.[7] Counting begins
from the carboxylic acid end. Double bonds are
labelled with cis-/trans- notation or E-/Z- notation,
where appropriate. This notation is generally more
verbose than common nomenclature, but has the
advantage of being more technically clear and
descriptive.
• Example : (9Z)-octadecenoic acid (oleic acid)

26. •
•
Delta-x nomenclature
In Δx (or delta-x) nomenclature, each double
bond is indicated by Δx, where the double bond is
located on the xth carbon–carbon bond, counting
from the carboxylic acid end. Each double bond is
preceded by a cis- or trans- prefix, indicating the
conformation of the molecule around the bond.
For example, linoleic acid is designated "cis-Δ9,
cis-Δ12 octadecadienoic acid". This nomenclature
has the advantage of being less verbose than
systematic nomenclature, but is no more
technically clear or descriptive.

27. n-x Nomenclature
• n−x (n minus x; also ω−x or omega-x)
nomenclature both provides names for individual
compounds and classifies them by their likely
biosynthetic properties in animals. A double bond is
located on the xth carbon–carbon bond, counting from
the terminal methyl carbon (designated as n or ω)
toward the carbonyl carbon.
• For example, α-Linolenic acid is classified as a n−3 or
omega-3 fatty acid, and so it is likely to share a
biosynthetic pathway with other compounds of this
type. The ω−x, omega-x, or "omega" notation is
common in popular nutritional literature, but IUPAC
has deprecated it in favor of n−x notation in technical
documents

29. Hydrogenation
O
CH2
O
C
(C H 2 ) 5 C H C H (C H 2 ) 7 C H 3
O
CH
O
C
Ni
(C H 2 ) 5 C H C H (C H 2 ) 7 C H 3
+ 3H2
O
CH2
O
C
(C H 2 ) 5 C H C H (C H 2 ) 7 C H 3
29

30. Product of Hydrogenation
30
O
CH2
O
C
(C H 2 ) 1 4 C H 3
O
CH
O
C
(C H 2 ) 1 4 C H 3
O
CH2
O
C
(C H 2 ) 1 4 C H 3
Hydrogenation converts double bonds in oils
to single bonds. The solid products are used
to make margarine and other hydrogenated
items.

31. Hydrolysis
31
Triglycerides split into glycerol and three
fatty acids (H+ or enzyme catalyst)
O
CH2
O
C
(C H 2 ) 1 4 C H 3
O
CH
O
C
H
(C H 2 ) 1 4 C H 3
+
+3 H 2O
O
CH2
O
C
(C H 2 ) 1 4 C H 3
CH2
OH
CH
OH
CH2
OH
O
+
3 HO
C
(C H 2 ) 1 4 C H 3

32. Saponification and Soap
32




Hydrolysis with a strong base
Triglycerides split into glycerol and the salts
of fatty acids
The salts of fatty acids are “soaps”
KOH gives softer soaps

33. O
CH2
O
C
(C H 2 ) 1 6 C H 3
O
CH
O
C
(C H 2 ) 1 6 C H 3
+ 3 N aO H
O
CH2
O
C
(C H 2 ) 1 6 C H 3
C H2
OH
CH
OH + 3 N a
C H2
OH
O
+ -
O
C
(CH 2 ) 14 C H 3
s a lts o f fa tty a c id s (s o a p s )
33

36. Explanation




The presence of a soap or a detergent in
water facilitates the wetting of all parts of
the object to be cleaned, and removes
water-insoluble dirt by incorporation in
micelles
The surfactant molecules reversibly
assemble into polymolecular aggregates
called micelles.
By gathering the hydrophobic chains
together in the center of the micelle,
disruption of the hydrogen bonded structure
of liquid water is minimized, and the polar
head groups extend into the surrounding
water where they participate in hydrogen
bonding.
These micelles are often spherical in shape,
but may also assume cylindrical and
branched forms, as illustrated on the right.
Here the polar head group is designated by
a blue circle, and the nonpolar tail is a zig-