fattyacid.ppt useful for under graduate student

Dr. Prashant Raut,
Assistant Professor,
Soil Science and Agricultural Chemistry, Dr. PDKV, Akola

1. Long straight-chain carboxylic acids no branching
Most common chains range from 10–20 carbons in
length
Usually, an even number of carbons in the chain,
including the carboxyl carbon
Can be saturated or unsaturated, but usually no other
functional groups present
Any fatty acid that cannot be synthesized by the body is
called an essential fatty acid

2. The COOH gives it an
acid property.
The 3….dots represent the
chain is very long.

3. Solubility
>Longer chains
•more hydrophobic, less soluble.
>Double bonds increase solubility.
Melting points
•Depend on chain length and saturation
•Double bonds lead chain disorder and low melting
temperature.
•Saturated FAs are solids at Room Temperature.
Unsaturated Fas are liquid at Room Temperature.

4. Carbon Atoms: Double
Bonds
MeltingPoint (° C)Common Nam e
Satur at ed Fat ty Acid s
12: 0 Lauric acid 44
14: 0 Myristic acid 58
16: 0 Palmitic acid 63
18: 0 Ste aric acid 70
20: 0 Arachidic acid 77
Uns atu rat ed Fatt y Acids
16: 1 Palmitoleic acid 1
18: 1 Oleic acid 16
18: 2 Linole ic acid -5
18: 3 Linole nic acid -11
20: 4 Arachidonic acid -49

5. The Length of the Carbon Chain
long-chain
medium-chain
short-chain
The Degree of Unsaturation
saturated
unsaturated
The Location of Double Bonds
omega-3 fatty acid
omega-6 fatty acid

7. 
Unsaturated FAs have at
least one double bond
(C=C) in one of the fatty
acids

11. Polyunsaturated fatty acid (PUFA) are identified by
position of the double bond nearest the methyl end (CH
3)
of the carbon chain; this is described as a omega
number.
If PUFA has first double bond 3 carbons away from the
methyl end => omega 3 FA
6 carbons from methyl end => omega 6 FA

12. Saponification is the base-catalyzed hydrolysis of
an ester
Products of the reaction are
An alcohol
An ionized salt which is a soap
Soaps have a long uncharged hydrocarbon tail
Also have a negatively charged carboxylate group at end
Form micelles that dissolve oil and dirt particles

13. Hydrogenation is an addition reaction
Unsaturated fatty acids can be converted to saturated fatty
acids
Hydrogenation is used in the food industry

15. An ester of glycerol
with three fatty acids.
Also known as
triacylglycerols
One type of lipid
categorised as simple
lipid.

16. Glycerides are lipid esters
A triglyceride places fatty acid chains at each
alcohol group of the glycerol.
O
O
O
CH
2
OCR1
CH OCR2
CH
2
OCR3
Glycerol
part
Fatty acid
chains

17. Physical properties depend on the fatty acid
components.
Melting point increases as the number of carbons in
its hydrocarbon chains increases and as the number
of double bonds decreases.
Oils: Triglycerides rich in unsaturated fatty acids are
generally liquid at room.
Fats: Triglycerides rich in saturated fatty acids are
generally semisolids or solids at room temperature.
TRIGLCEROLS

18. Triglycerides have typical ester and alkene chemical
properties as they are composed of these two groups:-
Saponification: replace H with salt from a strong base
Hydrolysis: produces the fatty acids and glycerol, a reverse of
formation
Hydrogenation: saturates the double bonds

19. Triglycerides undergo three basic reactions
These reactions are identical to those studied in
carboxylic acids.
Triglyceride
Glycerol
Fatty
Acids
Glycero
lFatty Acid Salts
More saturated
triglycerid
e