classification includes saturated,unsaturated(mono and poly) types

1. Presentation by : Parnavi .S.Kadam
Topic : Classification of Fatty acids
(Saturated and Unsaturated types)
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2. Fatty Acids
• DEFINITION:-PARTICULARLY IN BIOCHEMISTRY, IT IS
A LONG ALIPHATIC HYDROCARBON CHAIN WITH A
CARBOXYLIC ACID MOIETY ATTACHED TO IT,WHICH
MAY BE EITHER SATURATED OR UNSATURATED.
• FATTY ACIDS AND FATS ARE TWO DIFFERENT
TERMINOLOGIES
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3. Nomenclature of fatty acids
• Most fatty acids have 12 to 20 carbons
• Most chains have an even number of carbons
(synthesized from two-carbon units)
• IUPAC nomenclature: carboxyl carbon is C-1
• Common nomenclature: α,β,γ,δ,ε etc. from C-1
• Carbon farthest from carboxyl is ω
• General Formula:- CH3-(CH2)n-COO⁻
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4. Fatty acids differ from one
another in:
1)Length of the hydrocarbon tail.
2)Degree of unsaturation(double
bond).
3)Position of the double bonds in the
chain.
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5. General Structure

6. Difference between Saturated and Unsaturated fatty acids.
• The basic difference lies in the chemical structure.
1)Saturated fatty acid
• They have no double bonds in between the long
hydrocarbon chain,so they are straight and can be
packed closely together.
• Solid at R.T.(i.e high M.P)
• eg:a)Laurate(dodeconate)(C-12) (CH₃-(CH₂)₁₀-COO⁻)
b) Myristate(teradeconate)(C-14) (CH₃-(CH₂)₁₂-COO⁻)
c)Palmitate(hexadeconate)(C-16) (CH₃-(CH₂)₁₄-COO⁻)
d)Stearate(octadeconate)(C-18) (CH₃-(CH₂)₁₆-COO⁻)
• A normal example can be BUTTER(having the animal
origin). (6)

7. Eg : Stearate

8. 2)Unsaturated fatty acid
• They have atleast one double bond in between
the long hydrocarbon chain.
These double bonds causes the fatty acid chain to
“kink”which results in more fluidity.
• liquid at R.T.
How are the double bonds in fatty acids?
• Double bonds are generally cis
• Position of double bonds indicated by Δn, where
• n indicates lower numbered carbon of each pair
• Shorthand notation example: 20:4Δ5,8,11,14
• (total # carbons : # double bonds, Δ double bond
positions) (8)

9. Subtypes of unsaturated fatty acids
2a) Monounsaturated fatty acid
Eg:a)Palmitoleate(C-16)(cis-∆9-hexadecenoate)
b)Oleate(C-18) (cis-∆9-octadecenoate)
2b) Polyunsaturated fatty acid
Eg:a)Linoleate(C-18)(cis,cis-∆9,12-octadecadienoate)
b)Linolenate(C-18)
(cis,cis,cis-∆9,12,15-octadecatrienoate)
• An common example can be corn oil(having the
plant origin)
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10. Eg:Oleate(monounsaturated) &
Linolenate(polyunsaturated)
• Oleate • Linoleate

11. Structural relationships of major lipid classes

12. BRIEF SUMMARY:
• Saturated FA: no C-C double bond
• Unsaturated FA: atleast one C-C double bond
• Monounsaturated FA: only one C-C double bond
• Polyunsaturated FA: more than one C-C double
bond.
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13. Dietary fact
• While it's not practical to eliminate
saturated fat in your diet entirely, as it is
present in many foods, replacing
saturated fats with unsaturated fats in the
diet has been shown to lower blood
cholesterol – one of the risk factors in the
development of heart disease.
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