Structural features

Structural features

lipoproteins

complexes of lipids and proteins

that allow lipids to be transported in the aqueous environment of the blood

Fatty acids/FAs

Structure →

hydrocarbon chain with a carboxyl group (–COOH) at one end and a methyl group (–CH₃) at the other

amphipathic

cis isomer

results in folding and bending of the molecule 

• EX)  oleic acid

trans isomer

effect of extending the molecule (elaidic acid) into a linear shape similar to that of saturated fatty acids

Two systems for naming double-bond positions

(shorthand way to indicate the chemical structure of a
fatty acid):

1. Delta (Δ): Counts carbon positions from the carboxyl end (-COOH).

2. Omega (ω): Counts carbon positions from the methyl end (-CH3) or omega (ω), end of the hydrocarbon chain

   1. (ω) indicates the first double bond counting from the methyl end

Types of Fatty Acids →

• Saturated Fatty Acids

  • Short Chain Fatty Acids (SCFA)

  • Medium Chain Fatty acids

  • Long & Very Long Fatty Acids

• Monounsaturated Fatty Acids (MUFA):

• Polyunsaturated Fatty Acids (PUFA)

  • Omega-6 Fatty Acids

  • Omega-3 Fatty Acids

Saturated Fatty Acids (SFAs)

Contain no double bonds; every carbon atom in the chain is bonded to the maximum number of hydrogen atoms via single bonds

Short Chain Fatty Acids (SCFA)

Less than 6 carbons

ex) Acetic, Propionic, Butyric

Medium Chain Fatty acids (MCFAs)

6 to 12 carbons

Long and Very Long Fatty acids

13 to 21 carbons

22 or longer carbons

 Monounsaturated Fatty Acids (MUFA)

possessing one carbon–carbon double bond (C=C)

Polyunsaturated Fatty Acids (PUFA)

having two or more carbon–carbon double bonds

Short Chain Fatty Acids (SCFA)

Less than 6 carbons

ex) Acetic, Propionic, Butyric

Acetic

C2:0  (two-carbon unit)

Formula→ C2H4O2 

+* coenzyme A = Acetyl-CoA

Propionic acid

C3:0 (three-carbon unit)

Formula → C3H6O2

+ coenzyme A = *propionyl-CoA

• Is a converging pt for metabolism

What FA is acetic?

SCFA

Butyric

C4:0 (four-carbon unit)

 C4H8O2

 produced through → *fibers / bacteria

• When activated, it forms butyryl-CoA. Is primary, preferred energy source for colonocytes

What FA is butyric?

SCFA

Medium Chain Fatty acids/MCFA

ex)Lauric

What FA is lauric?

MCFA

Lauric acid

2:0 (two carbon unit)

C12H24O2v 

HDL Increases & overall Total Cholesterol-to-HDL ratio (hypercholesterolemic)

HDL is good or bad cholesterol?

Good

Long and Very Long Fatty acids

13 to 21 carbons(saturated)

22 or longer carbons (unsaturated)

Long Chain-saturated FAs (LC-SFAs)

Myristic acid*

Palmitic acid*

Stearic acid*

Arachidic acid

Lignoceric acid

Myristic acid

C14:0

C14H28O2

*Strong hypercholesterolemic effect (raises LDL)

Palmitic acid

C16:0

C16H32O2

*Most abundant dietary saturated fatty acid / Raises LDL and total cholesterol

Stearic acid

C18:0

C18H36O2

*Long-chain saturated fatty acid / Unique neutral effect on blood cholesterol levels

Unsaturated Very long FAs

Palmitoleic acid

Oleic acid

Linoleic acid*

α-linolenic acid*

Arachidonic

Eicosapentaenoic*

Docosahexaenoic*