Lipid synthesis Flashcards
where does lipid synthesis occur
cytosol of animal cells
describe overall process of lipid synthesis
-one acetyl coA reacts with many malonyl coA to form palmitic acid
reaction required to make malonyl coA?
(7x) acetyl CoA +Co2 +ATP —acetyl coA carboxylase–> malonyl coA +ADP + Pi
how to make palmitic acid
acetyl coA + 7malonyl coa+ 14(NADPH + H+) –> 8CoA + 6 H2O + 7NADp+ + 7Co2 + palmitic acid
where is NADPh made
hepatocytes and adipocytes (cytosol)
2 processes how NADPh is made
malate and pentose phsophate pathway
describe malate reaction
malate + NADP+ NADPH + H+ + pyruvate + Co2
describe how Acetyl CoA is made
citrate(matrix) –> citrate (cytosol) –citrate lyase–> oxaloacetate (and acetyl coA) –malate dehydrogenase–>malate
malate(cytosol)–>malate(matrix)–malate dehydrogenase–>oxaloacetate
malate->pyruvate(cytosol)->pyruvate(matrix)–pyruvate carboxylase–>oxaloacetate
describe pathway from CAC to form palmitic acid
citrate –citrate yase–> acetyl coA –acetyl CoA carboxylase–>malonyl coA –> palmitic acid
effect of increased citrate?
activates acetyl co A carboxylase to ensure pathway continues (allosteric)
effect of increased palmitic acid?
inhibits acetyl coA carboxylase so that not too much is made (end product/feedback inhibition)
effect of insulin?
activates citrate lyase to ensure pathway is channeled towards energy conservation not production (hormonal)
effect of noradrenaline/glucagon?
inhibits acetyl coA carboxylase; channels pathway towards energy producion (hormonal)
how are ketone bodies formed?
increased acetyl CoA and decreased CAC intermediates –> channeled towards ketoone body formation
- starvation (gluconeogenesis and decreased CAC intermediates)
- diabetes
