Term
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Definition
EFA
18:2
omega-6/2
vegetable oils, corn, soya |
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Term
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Definition
EFA
18:3
omega-3/3
grains, flax |
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Term
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Definition
EFA
20:4
omega-6/4
vegetable oils |
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Term
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Definition
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Term
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Definition
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Term
| Overview of fatty acid synthesis pathways (image) |
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Definition
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Term
| Sources of the primary FA precursor (acetyl CoA) in the cytoplasm |
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Definition
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Term
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Definition
unsaturated FA
18:1, vegetables (olive oil) |
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Term
| origin of building blocks of triacylglycerols |
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Definition
Acetyl CoA in the cytoplasm: b/c of the bulk of acetyl CoA is formed in the mito, it has to be transported to cytosol in the form of CITRATE
Mito: pyr -> OAA, acetyl CoA -> citrate
Cytosol: citrate -> OAA, acetyl CoA
OAA -> malate -> pyruvate
Sources of NADPH (reducing equivalents - 16 NADPH total are needed):
- Malic enzyme rxn: 8 NADPH
(malate -> pyr)
- PPP provides the bulk of the NADPH
(involves Glucose-6-P dehydrogenase, 6-phosphogluconate dehydrogenase)
Glycerol phosphate
- liver: glycerol K can phosphorylate glycerol
glycerol -glycerol K-> glycerol-3-P
- adipose: glucose is req'd
glucose -> DHAP -> glycerol-3-P
*G-3-P is the backbone of phosphatidic acid* |
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Term
Regulation of FA (triacylglycerol) synthesis
Long term regulation |
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Definition
*acetyl-CoA carboxylase*
enhanced acetyl-CoA synthesis:
- high carb/low fat diet
provides more substrate
excess CHO available
- insulin
decreased enzyme synthesis:
- high fat diet
doesn't bring about secretion of insulin!
- fasting/glucagon
*fatty acid synthetase*
- facilitates the assembly of the 2- and 3-C units into palmitic acid
- same as acetyl CoA carboxylase
enhanced enzyme synthesis on high carb/low fat diet, and vice versa |
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Term
| sources of carbon for FA synthesis |
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Definition
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Term
Acetyl-CoA carboxylase
- step?
short term regulation:
- allosteric activation/enhancement
- allosteric inhibition |
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Definition
*the rate-limiting step of FA synthesis*
acetyl CoA -> malonyl CoA
requires acetyl CoA carboxylase (and biotin)
prevents futile cycling
Allosteric activation/enhancement:
- citrate
- insulin
- dephosphorylation
Allosteric inhibition:
- long-chain acyl CoA
- glucagon
- phosphorylation (cAMP) |
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Term
| Rate limiting step in FA synthesis (image) |
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Definition
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Term
Fatty acid synthesis/metabolism
Role of malonyl CoA
(image) |
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Definition
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Term
| Relationship b/t structure of polyunsaturated EFA and prostaglandin biosynthesis |
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Definition
Prostacyclin:
- inhibits platelet aggregation
- lowers BP
- relaxes coronary arteries
Thromboxane:
- stimulates platelet aggregation
- raises BP
- constricts coronary arteries
Omega-3 FA tend to LOWER thrombotic tendencies
Omega-6 FA tend to RAISE thrombotic tendencies |
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Term
Prostaglandin synthesis (image)
- NSAIDS
- Steroid anti-inflammatories |
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Definition
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Term
| structural arrangements of macromolecular lipid complexes |
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Definition
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Term
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Definition
Palmitic: 16:0, dairy
Stearic: 18:0, meat |
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