Fatty acid

high-resolution terminology - matching measurements at high-resolution

Fatty acid

Description

Abbreviation: FA

Fatty acids are carboxilic acids with a carbon aliphatic chain. The fatty acids can be divided by the lenght of this chain, being considered as short-chain (4–8 carbons), medium-chain (6–12 carbons) and long-chain (14-22 carbons) fatty acids.

Long-chain fatty acids must be bound to carnitine to enter the mitochodrial matrix, in a reaction that can be catalysed by carnitine acyltransferase. For this reason, long-chain fatty acids, such as palmitate (16 carbons) is frequently supplied to mt-preparations in the activated form of palmitoylcarnitine. Fatty acids with shorther chains, as octanoate (8 carbons) may enter the mitochondrial matrix, however, in HRFR they are more frequently supplied also in the activated form, such as with octanoylcarnitine.

Once in the mitochondrial matrix, the fatty acid oxidation (FAO) occurs, generating acetyl-CoA, NADH and FADH2. In the fatty acid oxidation pathway control state electrons are fed into the F-junction involving the electron transferring flavoprotein (CETF). FAO cannot proceed without a substrate combination of fatty acids & malate, and inhibition of CI blocks FAO completely.

Reference: Gnaiger 2014 MitoPathways

MitoPedia topics: Substrate and metabolite 

Fatty acids used in HRFR

• Octanoylcarnitine (Oct)
• Palmitoylcarnitine (Pal)
• Octanoate (Oca)