Monounsaturated Fatty Acid Modification of Wnt Protein: Its Role in Wnt Secretion
Lipids Composed of C, H and few O Basic unit is fatty acid (glyceride) Triglyceride is the major...
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Transcript of Lipids Composed of C, H and few O Basic unit is fatty acid (glyceride) Triglyceride is the major...
Lipids
Composed of C, H and few O
Basic unit is fatty acid (glyceride)
Triglyceride is the major form of lipid = 3 fatty acids
Fats and oils
Monounsaturated Fatty Acids
Polyunsaturated Fatty Acids
Saturated Fatty Acids
Essential Fatty Acids
Energy yielding (9 kcal /gm)
Properties of Lipids
• Do not readily dissolve in water
• Fats are solid at room temperature
• Oils are liquid at room temperature
• Triglycerides are the main form of lipids in food and body (storage)
• Energy dense (9 kcal /gm)
The building block of lipids are fatty acids
omega end alpha end Note that all carbons have two hydrogens – this is a fully saturated fatty acid.
H H H H H H H H H H H H H H H H H O
H-C--C--C--C--C--C--C--C--C--C--C--C--C--C--C--C--C-C-OH
H H H H H H H H H H H H H H H H H
Triglycerides
(Ester bond)
Glycerol + 3 FA’s Triglyceride +
3 H20
H
H--C--OH
H--C--OH
H--C--OH
H
O
HO-C-R
O
HO-C-R
O
HO-C-R
+
H O
H--C--O--C--
O
H--C--O--C--
O
H--C--O--C--
H
R + H2O
R + H20
R + H20
Triglycerides
esterification desterfication
H
H--C--OH
H--C--OH
H--C--OH
H
Fatty Acid
Fatty Acid
Fatty Acid
+
H O
H--C--O--C--
O
H--C--O--C--
O
H--C--O--C--
H
Fatty Acid
Fatty Acid
Fatty Acid
Monounsaturated Fatty Acid Structure
omega end alpha end When two Hs are lost from two adjacent Carbons, a double bond is formed. This is an unsaturated fatty acid.
H H H H H H H H H H H H H H H O
H-C--C--C--C--C--C--C--C--C=C--C--C--C--C--C--C--C--C-OH
H H H H H H H H H H H H H H H H H
Polyunsaturated Fatty Acid Structure
omega end alpha end Two or more double bonds results in a polyunsaturated fatty acid.
H H H H H H H H H H H H H O
H-C--C--C--C--C--C=C--C--C=C--C--C--C--C--C--C--C--C-OH
H H H H H H H H H H H H H H H H H
The more double bonds, the lower the melting point of a fat/oil
• Beef fat or lard has a large amount of saturated fatty acids that are long. It is solid at room temperature.
• Butter has about the same number of saturated as unsaturated fatty acids. Butter is beginning to melt at room temperature.
• Vegetable oil is 100% unsaturated fatty acids. It is liquid at room temperature and will solidify at around –5 °F.
• What about vegetable shortening?????
The chain length has an effect on how liquid a fat/oil is at room temperature
• Long chain FA > 12 Carbons
• Medium chain FA 6 - 10 Carbons
• Short chain FA< 6 Carbons
Hydrogenation of Fatty Acids
• Process used to solidify an oil• Addition of H to C=C double bonds• Formation of trans fatty acid
Health Dangers of Excessive Trans Fatty Acid
• Raises LDL
• Lowers HDL
• Increases risk for heart disease
• Current intake is~3% of total kcals
• Soon to be on food labels
Minimize Intake of Trans Fatty Acid
• Limit use of hydrogenated fats– partially hydrogenated vegetable oil
• Limit deep-fried foods
• Limit high fat baked goods
• Limit use of non-dairy creamers
Essential Fatty Acids
Body can only make double bonds after the 9th carbon from the omega end
Needed for immune function, vision, cell membrane, and production of hormone-like compounds
Essential Fatty Acid; Omega-3 (alpha-linolenic acid)
omega end
alpha end 1st double bond is located on the 3rd carbon from
the omega end
H H H H H H H H H H H H H H H H H O
H-C--C--C=C--C--C =C--C--C=C--C--C--C--C--C--C--C--C-OH
H H H H H H H H H H H
Omega-3 Fatty Acids
Primarily from fish oil
Also found in canola or soybean oil
Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are related
Metabolized to form eicosanoids
Recommend intake of ~2 servings of fish per week
Omega 3 (Alpha-linolenic acid, C18:3)
2C
2H
Eicosapentaenoic acid (EPA, C20:5)
2C
2H
Docosahexaenoic acid (DHA, C22:6)
Eicosanoids
Essential Fatty Acid Omega-6 (alpha-linoleic acid)
omega end
alpha end 1st double bond is located on the 6th carbon from
the omega end
H H H H H H H H H H H H H O
H-C--C--C--C-- C--C =C--C--C=C--C--C--C--C--C--C--C--C-OH
H H H H H H H H H H H H H H H H H
Omega-6 Fatty Acid
• Found in vegetable oils
• Only need ~ 1 tablespoon a day
• Arachidonic acid can be made from omega-6
• Metabolized to form eicosanoids
Omega 6 (linoleic acid, C18:2)
2C
2H
Dihomo-gamma-linolenic acid (C20:3)
2H
Arachidonic acid (C20:4)
Eicosanoids
Eicosanoids
Eicosanoids are a group of hormone-like compounds
Regulators of blood pressure, childbirth, clotting, immune responses, inflammatory responses, & stomach secretions
By-pass the blood stream and work in the area of origin
Eicosanoids Have Different Effects
Omega-6 eicosanoids; Archidonic acidincrease blood cot
increase inflammatory responses
Omega-3 eicosanoids, DHA, EPA decrease blood clotting
reduces heart attack
excess may cause hemorrhagic stroke???
Eicosanoid has different effect on different tissues