Lipid 3 Flashcards
Precursor for fatty acid synthesis?
Acetyl CoA
How is acetyl CoA
Through glycolysis
Through fatty acid degradation
Steps to synthesise fatty acids?
- Acetyl CoA to acetyl CoA cytoplasm
- Link two carbons together
- Palmitate to other fatty acids (C16 and C18 are most common)
What happens in the cytosol?
Anabolism
Formation of acyl-CoA
Where does synthesis and degradation take place?
Synthesis = cytosol Degradation= mitochondrial matrix
Discuss intermediates in FA synthesis vs FA degradation?
Synthesis= intermediate covalently linked to sulfhydryl groups of an acyl carrier protein (ACP) Degradation= intermediates covalently linked to sulphydryl group of coenzyme A
Enzyme comparison between FA synthesis and degradation?
Enzymes of FA synthesis in higher organisms are joined in a single system called fatty acid synthesis. Degradative enzymes are not associated
What’s the activated donor of two carbons to the elongated growing fatty acid chain?
Malonyl ACP (driven by CO2 release)
What’s the reductant in synthesis vs oxidants in degradation?
Synthesis= NADPH Oxidants= NAD and FAD
When does elongation of fatty acid synthesis stop?
At the formation of palmitate (C16)
What aid the further elongation and insertion of double bonds carried out by?
Other enzyme systems
What is the committed/irreversible step in fatty acid synthesis?
Formation of malonyl CoA
What does fatty acid synthesis start with?
Carboxylation of acetyl CoA to malonyl CoA
What is the formation of malonyl catalysed by?
Cytoplasmic enzyme acetyl CoA carboxylase 1
What have essential roles in regulating fatty acid synthesis and degradation of fatty acid metabolism?
Acetyl CoA carboxylase 1, acetyl CoA carboxylase 2, an isoenzyme of acetyl CoA carboxylase 1
