<P> Alpha - oxidation of phytanic acid is believed to take place entirely within peroxisomes . </P> <Ol> <Li> Phytanic acid is first attached to CoA to form phytanoyl - CoA . </Li> <Li> Phytanoyl - CoA is oxidized by phytanoyl - CoA dioxygenase, in a process using Fe and O, to yield 2 - hydroxyphytanoyl - CoA . </Li> <Li> 2 - hydroxyphytanoyl - CoA is cleaved by 2 - hydroxyphytanoyl - CoA lyase in a TPP - dependent reaction to form pristanal and formyl - CoA (in turn later broken down into formate and eventually CO). </Li> <Li> Pristanal is oxidized by aldehyde dehydrogenase to form pristanic acid (which can then undergo beta - oxidation). </Li> </Ol>

Alpha oxidation of fatty acid takes place in