4_3FASynthesis Flashcards
sphingomyelin
ceramide + phosphatidylcholine
Galactocerebroside
Ceramide + UDP-Gal
Glucocoserebroside
Ceramide + UDP-Glc
2 types of galactocerebrosides
sulfratide and globoside
Ganglioside
Ceramide + Glc + Gal + NANA
NANA =
sialic acid
Precursors of ceramide
palmitoyl-CoA and serine
Precursors to phosphatidylcholine
DAG + CDP-choline
How is choline activated to CDP-choline
ATP and CTP
Precursors to Phosphatidylinositol
Phosphatidic Acid (activated with CTP -- CDP-DAG) Inositol
How is cardiolipin synthesized?
CDP-DAG + Phosphatidylglycerol
palmitic acid structure
16:0
Where does elongation to greater than 16 FAs occur?
ER Elongase complex (also mito and peroxisomes)
Steps in Elongation
1) Rate-limiting condensation
2) keto-reduction
3) dehydration
4) enoyl reduction
How is FA synthesis different from beta-oxidation?
1) ACP
2) D-beta-OH
3) NADPH
4) Malonyl-CoA Precursor
What is the first committed and RLS of FA synthesis?
acetyl-coA carboxylase
What are the regulation points of fatty acid synthesis?
1) acetyl-CoA carboxylase
2) AL
3) CPT I
4) LPL
How is acetyl-coA carboxylase regulated?
activated by dephosphorylation (insulin)
How is CPTI regulated?
malonyl CoA inhibits
How is LPL regulated?
induced by insulin
How is HSL/AL regulated?
activated by GCG phosphorylation
What are the phases of FA synthesis?
1) Acetyl-CoA carboxylase
2) FAS
- - Priming
- - Elonation
- - Termination
How many steps in the reduction cycle?
4 (3-7 rounds)
What is the mechanism of KAS?
Claisen
How many steps in the priming phase of FAS?
2
How many steps in the termination phase of FAS?
1
What is the common group of CoA/ACP
phosphopantetheine group (prosthetic if ACP)
ACAT acronym
acetyl-coA : ACP transacetylase
What are lipids’ roles in TB?
encapsulation of Mycobacterium
What are lipids’ roles in cancer?
FA biosynthesis provides oxidized co-factors (NADP, FAD) for anaerobic metabolism
