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FATSFats and oils are chemically similar, but differ

inphysical states.

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Fats : - found in animals

- solid in room temperature

- butter and tallow (types of fat)

Oil : - found from plants

- liquid in room temperature

- palm oil, coconut oil, sunflower oil

- Fats and oil are mixtures of different esters.- Fats are formed from 3 molecules of long-chain carboxylic acids called fatty acidswith 1 moleculesofalcohol called glycerol.

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H

H C OH

H C OH

H C OH H

Fatty acids- R

1, R

2, R

3contains

12 to 18 carbon

atoms per molecule

- R1

, R2

, R3

are three

alkyl groups which

may be the same or

different

- group: carboxilic acid

O

HO C R1

O

HO C R2

O

HO C R3

Glycerol- propane-1,2,3-triol- group: alcohol

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Formation of a fat/oil molecule - ESTER

H

H C OH

H C OH

H C OH H

O

OH C R1

O

OH C R2

O

OH C R3

H O

H C O C R1 O

H C O C R2

O

H C O C R3

H

+ 3H2O

+

Break up

and rejoin

Break up

and rejoin

Break up

and rejoin

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Importance of fats and oils (5.2:12/5/2010)- energy

- nutrients

- thermal insulation- protection to internal organ

[Text book: Figure 2.34 pg. 86]

Saturated and unsaturated fats- Fat or oil molecules is affected byparent fattyacids.

- Fatty acids can be differentiated in two ways;

i. the length of the carbon chains

(12 to 18 carbon atoms)ii. saturated or unsaturated

Saturated fatty acid- All carbon atoms joined together by

carbon-carbon single covalent bond.- example:

Lauric acid (12 carbon atoms)

Palmitic acid (16 carbon atoms)

Stearic acid (18 carbon atoms)5

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Unsaturated fatty acid- The carbon chain has one or more

carbon-carbon double covalent bond.

Example:

i. Oleic acid: monounsaturated fatty acid

(one carbon-carbon double bond)-

[no of C = 18, DB = 9&10]

ii. Linoleic acid: polyunsaturated fatty acid

(two carbon-carbon double bond)

[no. of C = 18, DB = 9&10, 12&13]

iii. Linolenic acid: polyunsaturated fatty acid

(three carbon-carbon dauble bond)

[no. of C = 18, DB = 9&10, 12&13,

15&16]

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Saturated Fats- Fats contain esters ofglycerol and saturated

fatty acids.

- Example:

i. Tristearin (glycerol + stearic acid)

ii. Tripalmitin (glycerol + palmitic acid)

Tristearin

H O

H C O C (CH2)

16 CH

3

O

H C O C (CH2)

16 CH

3

O

H C O C (CH2)

16 CH

3

H

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Tripalmitin

- Animal fats have large proportions of

saturated fats.

- They have high melting point and solids at

room temperature.

H O

H C O C (CH2)

14 CH

3

O

H C O C (CH2)

14 CH

3

O

H C O C (CH2)

14 CH

3

H

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Unsaturated Fats- Fats contain esters ofglycerol and

unsaturated fatty acids.

Example:

i. Triolein (glycerol + oleic acid)

H O H C O C (CH

2)

7 CH CH (CH

2)

7 CH

3

O

H C O C (CH2

)7

CH CH (CH2

)7

CH3

O

H C O C (CH2)

7 CH CH (CH

2)

7 CH

3

H

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Example:

i. Trilinolein (glycerol + linoleic acid)

Example:

i. Trilinolenin (glycerol + linolenic acid)

H O

H C O C (CH2)7 CH CH CH2 CH CH (CH2)4 CH3 O

H C O C (CH2)

7 CH CH CH

2 CH CH (CH

2)

4 CH

3

O

H C O C (CH2

)7

CH CH CH2

CH CH (CH2

)4

CH3

H

H O

H C O C (CH2)

7 CH CH CH

2 CH CH CH

2 CHCH CH

2CH

3

O

H C O C (CH2)

7 CH CH CH

2 CH CH CH

2 CHCH CH

2CH

3

O

H C O C (CH2)7 CH CH CH2 CH CH CH2 CHCH CH2CH3

H

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Plant or vegetable oils contain a large

proportions of unsaturated fats.

- They have lower melting points and areliquids at room tempoerature.

Converted unsaturated fats to saturated fats

- Unsaturated fats can be converted intosaturated fats by process called catalytic

hydrogenation. / 180OC

The hydrogenation process is carried out by

bubbling hydrogen gas through hot, liquidoil in the presence of fine particles of nickelcatalyst.

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Effect of fats on health- Saturated fats (animal oil) will raise the level

of cholesterol.

- Cholesterol causes fatty deposites on the wall

of veins or arteries.

- Blood circulation is restricted and will raise

the blood presure

- Arteriosclerosis, can result in heart attack.- Unsaturated fats (plant oil) do not contain

cholesterol. Do not cause cardiovascular

problems.

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Uses of palm oil- Has many advantages.

- A cheaper, better and healthier oil.

[Text book: Figure 2.36 pg. 90]

Prepared by;

Kamal Ariffin Bin SaaimSMKDBL

http://kemhawk.webs.com

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