Lesson 5.2. Fatty Acids

Fatty Acids

simple, linear monocarboxylic acids

Saponifiable

• with fatty acids

• includes TAGs, glycerophospholipids, sphingophospholipids, sphingoglycolipids, and waxes

Nonsaponifiable

• without fatty acids

• include sterols, sterol derivatives, eicosanoids, cholesterol, bile acids, steroids

Short-chain (SCFA)

Fatty Acids Classification by length:

• 4-6C

Medium-chain (MCFA)

Fatty Acids Classification by length:

• 8-10C

Long-Chain (LCFA)

Fatty Acids Classification by length:

• 12C or more

Saturated

Fatty Acids Classification by saturation:

• no C=C

Unsaturated

Fatty Acids Classification by saturation:

• at least 1 C=C

Saponification

3 Fatty Acids + 3 NaOH —> 3 fatty acid salts + 3 H2O

dual polarity

1. The structure of soap is such that they exhibit a “_________”

2. The a.________ portion of the carboxylate ion is nonpolar while the b.______ portion is polar.

3. This dual polarity for the fatty acid salt ____________ which is representative of all fatty acid salts present in soap.

1 = ?

hydrocarbon

1. The structure of soap is such that they exhibit a “_________”

2. The a.________ portion of the carboxylate ion is nonpolar while the b.______ portion is polar.

3. This dual polarity for the fatty acid salt ____________ which is representative of all fatty acid salts present in soap.

2.a. = ?

carboxyl

1. The structure of soap is such that they exhibit a “_________”

2. The a.________ portion of the carboxylate ion is nonpolar while the b.______ portion is polar.

3. This dual polarity for the fatty acid salt ____________ which is representative of all fatty acid salts present in soap.

2.b. = ?

sodium stearate

1. The structure of soap is such that they exhibit a “_________”

2. The a.________ portion of the carboxylate ion is nonpolar while the b.______ portion is polar.

3. This dual polarity for the fatty acid salt ____________ which is representative of all fatty acid salts present in soap.

3 = ?

nonpolar oil or grease

Soap solubilizes oily and greasy materials in the following manner:

The nonpolar portion of the carboxylate ion dissolves in the a._________________, and the polar carboxylate portion dissolves in the b._____________.

The penetration of the oil or grease by the nonpolar end of the carboxylate ion is followed by the formation of __________.

The carboxyl groups and water molecules are attracted to each other, causing the __________________ of the micelle.

polar water

Soap solubilizes oily and greasy materials in the following manner:

1. The nonpolar portion of the carboxylate ion dissolves in the a.____________, and the polar carboxylate portion dissolves in the b._____________.

2. The penetration of the oil or grease by the nonpolar end of the carboxylate ion is followed by the formation of __________.

3. The carboxyl groups and water molecules are attracted to each other, causing the __________________ of the micelle.

1.b. = ?

micelles

Soap solubilizes oily and greasy materials in the following manner:

1. The nonpolar portion of the carboxylate ion dissolves in the a.____________, and the polar carboxylate portion dissolves in the b._____________.

2. The penetration of the oil or grease by the nonpolar end of the carboxylate ion is followed by the formation of __________.

3. The carboxyl groups and water molecules are attracted to each other, causing the __________________ of the micelle.

2 = ?

solubilization

Soap solubilizes oily and greasy materials in the following manner:

1. The nonpolar portion of the carboxylate ion dissolves in the a.____________, and the polar carboxylate portion dissolves in the b._____________.

2. The penetration of the oil or grease by the nonpolar end of the carboxylate ion is followed by the formation of __________.

3. The carboxyl groups and water molecules are attracted to each other, causing the __________________ of the micelle.

3 = ?

lowers water solubility

Polarity/Solubility:

• ↑carbons ↑lipophilicity ↑ lipophilicity = ?

increases MP

Melting point

• ↑carbons ↑IMF = ?

decreases MP

Melting point

• Double bonds – cause kinks that bend the structure (similar to branching) - ↓IMF = ?

Saturated

• contain only C-C single molecules

• compact molecules

• have a relatively high melting points

Caproic

Saturated Fatty Acids:

• 6 Carbons

• found in butter and goat’s milk

• gives a strong odor and flavor

• used in flavoring agents and in the manufacture of esters and perfume

Caprylic

Saturated Fatty Acids:

• 8 Carbons

• Has antimicrobial and antifungal properties

• used in medical foods, skin disinfectants, and dietary supplements

• helps maintain gut health

Capric

Saturated Fatty Acids:

• 10 Carbons

• Used in soap and detergent production

• has antimicrobial effects

• also found in medium-chain triglycerides (MCTs) for quick energy

Lauric

Saturated Fatty Acids:

• 12 Carbons

• Main fatty acid in coconut oil

• has antiviral, antibacterial, and antifungal properties

• used in soaps, cosmetics, and detergents

Myristic

Saturated Fatty Acids:

• 14 Carbons

• Found in nutmeg oil, butterfat, and coconut oil

• helps anchor proteins to membranes (myristoylation)

• used in cosmetics and fragrance formulations.

Palmitic

Saturated Fatty Acids:

• 16 Carbons

• Most common saturated fatty acid in the body

• serves as an energy source and precursor for other lipids

• used in soap and cosmetics manufacturing

Stearic 

Saturated Fatty Acids:

• 18 Carbons

• Found in animal fats and cocoa butter

• used in candles, soaps, lubricants, and as a hardening agent in cosmetics

• also metabolized for energy

Arachidic

Saturated Fatty Acids:

• 20 Carbon

• Found in peanut oil and corn oil

• used in lubricants and waxes

• serves as a minor energy source

Behenic

Saturated Fatty Acids:

• 22 Carbon

• Found in ben oil (from Moringa seeds)

• used in hair conditioners and skin moisturizers for its smooth texture and water-resistant properties

Lignoceric

Saturated Fatty Acids:

• 24 Carbons

• Found in peanut oil and wood tar

• component of sphingolipids in nerve cell membranes

• used in polishes, lubricants, and cosmetics

Unsaturated Fatty Acids

• Contain at least one C=C

• Not as compact as saturated

• Have relatively low melting points

• Either monounsaturated (1 C=C) or polyunsaturated (more than 1)

Delta notation

A:B^ΔC

Omega (ω/n) number

number of carbons from the last one (omega) before reaching the first double bond

Omega-3 Fatty Acids

• found in fish oils, but not those from plant sources, activate peroxisome proliferator-activated receptor-alpha (PPAR-a) and can induce reduction of triglycerides in some patients

• have anti-inflammatory and antiarrhythmic activities

• available over the counter as triglycerides from marine sources or as a prescription medication containing ethyl esters

vegetable oils

The omega-6 fatty acids present in __________ may cause triglycerides to increase

Linolenic acid

• 18 : 3^Δ9,12,15

• precursor of DHA (Docosahexaenoic acid) and EPA (Eicosapentaenoic acid)

Arachidonic acid

• 20 : 4^Δ5,8,11,14

• precursor of eicosanoids

20 carbons

Eicosanoids contains:

Prostaglandins (PG)

Eicosanoids:

• inflammation

Leukotrienes

Eicosanoids:

• brochoconstriction

Thromboxanes

Eicosanoids:

• clotting

essential fatty acids

Linoleic and linolenic acid are often called “__________________________” because they cannot be synthesized by the body.

Fatty Acids

• Most contain an even number of carbon atoms

• Carbon chain length is up to 24 carbon atoms.

Saturated

Classification Based on Degree of Unsaturation

• No double bonds are present in the carbon chain.

• Dietary effect is an increase in heart disease risk.

Monosaturated

Classification Based on Degree of Unsaturation

• One double bond is present in the carbon chain.

• Dietary effect is a decrease in heart disease risk.

Polyunsaturated

Classification Based on Degree of Unsaturation

• Two or more double bonds are present in the carbon chain.

• Dietary effect is "mixed"; there have been several conflicting studies relative to heart disease risk.

Cis Configuration

Classification Based on Configuration of Double Bond

• Naturally occurring fatty acids

Trans Configuration

Classification Based on Configuration of Double Bond

• result of hydrogenation process

• have effects on blood chemistry similar to those of saturated fatty acids

Omega-3

Classification Based on Location of Double Bond

• first double bond is three carbons away from the CH3 end of the carbon chain.

Linolenic Acid

example of Omega-3

Omega-6

Classification Based on Location of Double Bond

• First double bond is six carbons away from the CH3 end of the carbon chain.

Linoleic acid

example of Omega-6