4.4 understanding lipids
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Guess..
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4.4 Understanding Lipids
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The elements in lipids
Lipids are organic compounds made of C, Hand Olike carbohydratesThe ratio of Hatoms to Oatoms in moleculesof lipids is much higher then 2:1ratio incarbohydratesPercentage of O in lipid is lower than incarbohydrates
Ex: Olive oils (C57H104O6)Lipids are insoluble in water but soluble inother lipids and organic solvents (ex: alcoholand ether)
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The main types oflipids
Fats Oils
PhospholipidsWaxes
Steroids
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Waxes
- found on the cuticles of epidermis of leaves,fruits and seeds and also in sebum (excreted fromoil glands contains wax that soften our skin)
Phospholipids
- important components in the formation ofplasma membrane
Steroids
- complex organic compounds which includecholestrol and hormones (testosterone, estrogenand progesterone)
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The components of fats and oils
Lipids which are solids at room temperatureare called fatsLipids which are liquid at room temperature
are called oilsEach molecule of fat and oils consists of onemolecule of glyceroland threemolecules offatty acids
Fats and oils are called triglyceridesbecause they are formed from threemolecules of fatty acids
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The formation and breakdown of fatsand oils
Fat and oils (triglycerides) are formed throughthe condensationof one moleculeof glycerolandthree moleculesof fatty acids
Triglycerides can also be broken downinto fattyacidsand glycerolby hydrolysis reaction
+ + 3 H2O
condensation
hydrolysis
glycerol3 molecules
of fatty acidstriglycerides water
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Differences between saturated fats and
unsaturated fats
Saturated fats Comparisons Unsaturated fats
Contain fatty acids
which do not have
any double bonds
between carbon
atoms(all the
bonds between Catoms have the
maximum number
of H atoms)
The presence of
double bonds
between C atoms
in fatty acids
Contain fatty acids
that have double
bonds between
carbon atoms(C
atoms are not
bonded to themaximum number
of H atoms)
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Saturated fats Comparisons Unsaturated fats
-C-C-C-C- Structure -C-C=C-C-
Cannot form anychemical bonds with
other atoms or react
with additional H
atom
Ability to reactwith an
additional H
atom
Can form any chemicalbonds with other atoms
or react with additional
H atom
Solid
Condition at
room
temperatureLiquid
Contain more
cholesterol
Cholesterol level Contain less cholesterol
Animal fats like butter Examples Vegetables oils like corn
oil and palm oil
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Homework
State the elements in lipids
State the main types of lipids
Explain briefly the formation and breakdown
of fats and oils
Explain why it is better to cook with
unsaturated fats when compared to saturated
fats
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Lipids
Elements: carbon, hydrogen, oxygen
Types:
tryglycerides
fats and oils
phospholipids main component in
membrane
steroids complex organic compounds in
cholestrol and hormones
waxes long chain molecules
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Tryglyserides + water 3 fatty acids + glycerol
hydrolysis
condensation
Fats
saturated
unsaturated
What are the differences between saturated fats and unsaturated fats?
Discuss and state the differences in a table.
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H H H H
- C - C - C - C -
H H H H
H H H H
- C - C = C - C -
H H
Saturated fats Unsaturated fats
Double bond
Unsaturated fats with one double bond are cal led
mo nounsaturated fats. Those with more than two dou ble
bonds are cal led po lyun saturated fats.
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Saturated fats Unsaturated fats
Saturated fats do not have any
double bond.
Unsatgurated fats have st
least one double bond.
Saturated fats Cannot form
any bond with other atom
Unsaturated fats are able to
react with other atom.
Saturated fats are in solid
form at room temperature.
Unsaturate fats are in liquid
form at room temperature.
Saturated fats Contain morecholesterol.
Unsaturated fats have lesscholesterol
One example of saturated fats
is butter.
One example of unsaturated
fats is corn oil
The differences between saturated fats and
Unsaturated fats
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Proteins
The basic units of proteins are
amino acids.
Build new cells for growth and
renew damaged tissues.
Important components of the
plasma membrane.Components of enzymes,
antibodies and certain
hormones.
Structure components of keratinin skin, collagen in bones and
myosin in muscle tissues.
Used to synthesis haemoglobin.
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