o Citrate partially activate the phosphorylated acetyl-CoA carboxylase(similar to how AMP partially active the dephosphorylated glycogen phosphorylase) o In plants, acetyl-CoA carboxylase is activated by a increase of mg 2+ concentration and decrease of H concentration that accompany illumination o Malonyl-CoA inhibits carnitine acyltransferase)
⚫ Citrate partially activate the phosphorylated acetyl-CoA carboxylase (similar to how AMP partially active the dephosphorylated glycogen phosphorylase). ⚫ In plants, acetyl-CoA carboxylase is activated by a increase of Mg 2+ concentration and decrease of H+ concentration that accompany illumination. ⚫ (Malonyl-CoA inhibits carnitine acyltransferase I)
Citrate Dephosphorylated A acetvI-COA citrate insulin triggers lyase ①← Carboxylase activation (active) Acetyl-COA acetyl-CoA glucagon, epinephrine carboxylase trigger phosphorylation/inactivation Malonyl-CoA Acetyl-CoA carboxylase o.o 400 is regulated by allosteric effectors and reversible phosphorylation (b) Palmitoyl-CoA a
Dephosphorylated acetyl-CoA Carboxylase (active) Acetyl-CoA carboxylase is regulated by allosteric effectors and reversible phosphorylation
Citrate partially activate the phosphorylated acetyl-Coa carboxylase ATP ADP AMP-activated Citrate protein kinase Partially Active Inactive active carboxylase carboxylase carboxylase Protein Citrate phosphatase 2A P HO
Citrate partially activate the phosphorylated acetyl-CoA carboxylase
9. Palmitate can be further elongated and desaturated in smooth er Palmitoyl-CoA can be further elongated by the fatty acid elongation system present mainly in the smooth endoplasmic reticulum, with two carbon units also donated by malonyl-COA Palmitoyl-CoA and Stearoyl-CoA can be desaturated between C-9 and C-10 to produce palmitoleate, 16: 1(49), and oleate, 18: 1(49) respectively
9. Palmitate can be further elongated and desaturated in smooth ER ⚫ Palmitoyl-CoA can be further elongated by the fatty acid elongation system present mainly in the smooth endoplasmic reticulum, with twocarbon units also donated by malonyl-CoA. ⚫ Palmitoyl-CoA and Stearoyl-CoA can be desaturated between C-9 and C-10 to produce palmitoleate, 16:1( 9 ), and oleate, 18:1( 9 ) respectively
o The double bonds are introduced by the catalysis of fatty acyl-Coa desaturase(a mixed-function oxidase), where both the fatt acyl group and nadPh are oxidized by o2 o The electrons of nadph are transferred to o via Cyt b5 reductase and cytochrome b o further desaturation of oleate occur on phosphatidylcholine and is catalyzed b another desaturase. which is present only in plant cells o Linoleate and linolenate. needed to make other polyunsaturated fatty acids like arachidonate are essential fatty acids for mammals
⚫ The double bonds are introduced by the catalysis of fatty acyl-CoA desaturase (a mixed-function oxidase), where both the fatty acyl group and NADPH are oxidized by O2 . ⚫ The electrons of NADPH are transferred to O2 via Cyt b5 reductase and cytochrome b5 . ⚫ Further desaturation of oleate occur on phosphatidylcholine and is catalyzed by another desaturase, which is present only in plant cells. ⚫ Linoleate and linolenate, needed to make other polyunsaturated fatty acids like arachidonate are essential fatty acids for mammals