In: Biology
Last step of lipid biosynthesis is the 3 addition methyl group on carbon atoms 4 & 14 are removed to produce zymosterol.
Then double bond migrates from 8-9 position to 5-6 position ,when desmosterol is formed. Desmosterol is present in fetal brain. It is absent in adult brain.
Finally double bind in side chain (between C-24 &C-25 ) is reduced by NADPH when cholesterol is formed.
Yes it is the pathway for phosphoglyceride because phosphatidate is a triglyceride & phosphoglycerides are derived from phosphatidate by the formation of an ester bond between the phosphate group of phosphatidate and the hydroxyl group of one of several alcohols.