an analysis of the available data on the cytidine pathway for the synthesis of phosphatidylcholine and phosphatidylethanolamine , by the logic derived from the theoretical principles of metabolic regulation , shows that the first two reactions catalysed by choline ( ethanolamine ) kinase and phosphocholine ( phosphoethanolamine ) cytidylyltransferase are rate-limiting , whereas the phosphocholine ( phosphoethanolamine ) transferase step is near equilibrium in rat liver .
C0008405
choline
C0031716
phosphocholine