Presentation
Lipids
Michaela Barošová, Lukáš Malina
Properties of Lipids
The Lipids are esters of long chain fatty acids and alcohols
(glycerol).
They are a large and diverse group of naturally occuring organic
compounds that are
 generally insoluble in water – they are hydrophobic
 soluble in nonpolar solvents such as ether, chloroform, aceton
etc.
There is a great structural variety among the lipids.
diverse - různorodý
occuring – vyskytující se
Functions of Lipids
1.
2.
3.
4.
5.
store and source of energy for animals and people
solvent (for the lipid soluble vitamins such as A, D, E, K)
structural components of biological membranes
protective function – they protect some organs in human
body (kidneys)
both lipids and lipid derivatives serve as vitamins and
hormones
store – rezerva, zásoba
source – zdroj
protective - ochranný
serve - sloužit
Classification of Lipids
1.
•
•
•
2.
•
•
Homolipids
Fatty acids and their
derivatives
Triacylglycerols
Wax esters
Heterolipids
Phospholipids
Sphingolipids
wax - vosk
Fatty Acids
•
•
•
their name mostly reflect
their sources
natural fatty acids may be
saturated or unsaturated
linoleic and linolenic fatty
acids are essential - their
absence in the human diet is
connected with health
problems (increased
dehydration )
reflect – odrážet
saturated - nasycený
Saturated
Unsaturated
Common
name
lauric acid
Common
name
palmitoleic
acid
myristic acid
palmitic acid
stearic acid
oleic acid
linoleic acid
linolenic acid
arachidic acid
arachidonic
acid
Triacylglycerols
•
•
•
•
•
the triesters of fatty acids with glycerol (1,2,3trihydroxypropane) - CH2OHCHOHCH2OH
are contained both in plants and animals
represent one of the major food group of our diet
solid at room temperature are classified as fats (occur
mainly in animals)
liquid are called oils (mainly in plants, but
triacylglycerols from fish are also oils)
Triacylglycerols - continued
•
•
fats have a predominance of
saturated fatty acids
oils are composed largely of
unsaturated acids
herring – sleďový
corn – obilí
peanut – burský oříšek
Animal fats
butter
human fat
herring oil
Plant oils
coconut
corn
olive
soyabean
peanut
Reactions of Triacylglycerols
•
the acid-catalyzed hydrolysis is used for
production of candles:
CH2–O–COR1
CH2–OH
│
│
CH–O–COR2 + 3H2O  CH–OH +
│
│
CH2–O–COR3
CH2–OH
R1–COOH
R2–COOH
R3–COOH
Reactions of Triacylglycerols continued
•
the base-catalyzed hydrolysis (saponification) is used
for production of soaps
• potassium soaps are soft and were then converted to
the harder sodium soaps by washing with salt solution
CH2–O–COR1
CH2–OH
│
│
CH–O–COR2 + 3NaOH  CH–OH +
│
│
CH2–O–COR3
CH2–OH
R1–COONa
R2–COONa
R3–COONa
Waxes
•
are esters of fatty acids with long chain monohydric alcohols
(one hydroxyl group)
• waxes are widely distributed in nature
• the leaves and fruits of many plants have waxy coatings –
protect them from dehydration and small predators
• examples: spermaceti: CH3(CH2)14CO2-(CH2)15CH3
beeswax: CH3(CH2)24CO2-(CH2)29CH3
Phospholipids
•
•
•
structural components of biomembranes
hydrophobic domain: composed largely of fatty acids
hydrophilic domain: containes phosphate or other polar groups
Sphingolipids
•
•
important components of animal and plant membranes
contain long – chain amino alcohol, in animals sphingosine
compose – skládat se
sparmaceti - vorvaňovina
beeswax – včelí vosk
References
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•
http://education.yahoo.com/reference/encyclopedia/entry/lipid
http://encyclopedia.wikipedia.org/wiki/lipid
http://biology.clc.uc.edu/couses/bio104/lipids.htm
http://www.cem.msu.edu/reusch/VirtualText/lipids.htm
Thank you for your attention