4.4 understanding lipids

8/13/2019 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.

4.4 understanding lipids

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