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9 Cards in this Set
- Front
- Back
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Characteristics of saturated fatty acids |
1. No double bonds 2. Varying lengths 3. Not essential - fatty acid synthase can synthesize saturated fatty acids that are up to 16-C long 4. Elongases can extend fatty acids to make them longer |
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Interpretation of abbreviated names for fats |
18:2 n-6 18 carbons 2 double bonds (db) Closest db to the omega (methyl) end is 6C away alpha end = carboxyl end |
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Non-Essential FAs |
Can make MUFAs (non-essential) Acetyl CoA →FAS→ 16:0 (palimate) 16:0 →elongase→ 18:0 18:0 →Δ9 desaturase→ 18:1 n-9 Adds double bond on 9th carbon from alpha end |
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Essential vs. Conditionally Essential FAs |
Essential (must get through diet) Linoleic Acid (18:2 n-6) or α-LinolenicAcid (18:3 n-3) Can't make this fatty acid because we don't have a Δ10/13 desaturase Can't insert a double bond 6 carbons in from the omega end Conditionally Essential Arachidonic Acid (20:4 n-6) (body can't produce) BUT eat Linoleic Acid (18:2 n-6) → elongate & desaturate to get 20:4 n-6 Either eat 20:4 n-6 or eat enough 18:2 n-6 to convert it EPA (20:5 n-3) or DHA (22:6 n-3) BUT eat α-Linolenic Acid → elongate & desaturate to get EPA + DHA Either eat EPA & DHA or eat enough α-Linolenic Acid to convert it |
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MUFAs |
One double bond Varying lengths Fatty acid synthase can synthesize FA up to 16C long Elongases extend MUFA to make them longer Desaturases add double bonds to make common MUFAs |
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Omega-3 PUFA (n3-PUFA) ESSENTIAL |
More than one double bond Varying lengths First double bond b/w 3rd and 4th carbon from omega end Elongase lengthen short dietary n3-PUFA BUT no desaturase that can add double bonds far enough from alpha end to make n3-PUFA from palmitate (16:0) |
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Omega-6 PUFA (n6-PUFA) |
More than one double bond Varying lengths First double bond b/w 6th and 7th carbon from omega end Elongase lengthen short dietary n6-PUFA BUT no desaturase that can add double bonds far enough from alpha end to make n6-PUFA from palmitate (16:0) |
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How much do we need? Linoleic Acid α-Linolenic Acid DHA/EPA |
Linolenic Acid: 4-20 grams of 18:2 n-6 α-Linolenic Acid: ~1-1.6 grams of 18:3 n-3 DHA/EPA: >250mg |
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Do Canadians get enough n-3 PUFA? |
α-Linolenic Acid) 18:3 n-3 EPA + DHA = No |
