Difference between revisions of "Fatty acid oxidation"

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Fatty acid oxidation

Description

Fatty acid oxidation (β-oxidation) is a multi-step process by which fatty acids are broken down to generate acetyl-CoA, NADH and FADH₂ for further energy production. Fatty acids (short chain with 4–8, medium-chain with 6–12, long chain with 14-22 carbon atoms) are activated by fatty acyl-CoA synthases (thiokinases) in the cytosol. The outer mt-membrane enzyme carnitine palmitoyltransferase 1 (CPT-1) generates an acyl-carnitine intermediate for transport into the mt-matrix. Octanoate, but not palmitate, (eight- and 16-carbon saturated fatty acids) may pass the mt-membranes, but both are frequently supplied to mt-preparations in the activated form of octanoylcarnitine or palmitoylcarnitine.

Electron-transferring flavoprotein complex (CETF) is located on the matrix face of the inner mt-membrane, and supplies electrons from fatty acid β-oxidation (FAO) to CoQ. FAO cannot proceed without a substrate combination of fatty acids & malate, and inhibition of CI blocks FAO completely. Fatty acids are split stepwise into two carbon fragments forming acetyl-CoA, which enters the TCA cycle by condensation with oxaloacetate (CS reaction). Therefore, FAO implies simultaneous electron transfer into the Q-junction trough CETF and CI.

Abbreviation: FAO

Reference: Gnaiger 2014 MitoPathways

MitoPedia methods: Respirometry

MitoPedia topics: Substrate and metabolite

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 {{MitoPedia
 |abbr=FAO
-|description=Fatty acid oxidation (β-oxidation) is a multi-step process by which fatty acids are broken down to generate acetylCoA, NADH and FADH2 for further energy production. Fatty acids (short chain with 4–8, medium-chain with 6–12, long chain with 14-22 carbon atoms) are activated by fatty acyl-CoA synthases (thiokinases) in the cytosol. The outer mt-membrane enzyme carnitine palmitoyltransferase 1 (CPT-1) generates an acyl-carnitine intermediate for transport into the mt-matrix. [[Octanoate]], but not [[palmitate]], (eight- and 16-carbon saturated fatty acids) may pass the mt-membranes, but both are frequently supplied to mt-preparations in the activated form of [[octanoylcarnitine]] or [[palmitoylcarnitine]].
+|description=Fatty acid oxidation (β-oxidation) is a multi-step process by which fatty acids are broken down to generate acetyl-CoA, NADH and FADH<sub>2</sub> for further energy production. Fatty acids (short chain with 4–8, medium-chain with 6–12, long chain with 14-22 carbon atoms) are activated by fatty acyl-CoA synthases (thiokinases) in the cytosol. The outer mt-membrane enzyme carnitine palmitoyltransferase 1 (CPT-1) generates an acyl-carnitine intermediate for transport into the mt-matrix. [[Octanoate]], but not [[palmitate]], (eight- and 16-carbon saturated fatty acids) may pass the mt-membranes, but both are frequently supplied to mt-preparations in the activated form of [[octanoylcarnitine]] or [[palmitoylcarnitine]].
 [[Electron-transferring flavoprotein complex]] (CETF) is located on the matrix face of the inner mt-membrane, and supplies electrons from fatty acid β-oxidation (FAO) to CoQ. FAO cannot proceed without a substrate combination of fatty acids & [[malate]], and inhibition of CI blocks FAO completely. Fatty acids are split stepwise into two carbon fragments forming acetyl-CoA, which enters the TCA cycle by condensation with oxaloacetate (CS reaction). Therefore, FAO implies simultaneous electron transfer into the [[Q-junction]] trough CETF and CI.