1-Acylglycerol-3-phosphate is synthesized from dihydroxyacetone phosphate, an acyl CoA molecule and NADPH + H+ in four reactions catalyzed by peroxisomal enzymes, either in the matrix of the organelle or associated with its membrane. These reactions are annotated here for palmityl (C16:0) CoA. In a series of less well-characterized reactions in the cytosol and endoplasmic reticulum, these molecules are converted to ether lipids (plasmalogens). The functions of plasmalogens are not well understood. They are an abundant subclass of phospholipids, however, and defects in their metabolism are associated with serious human disease (de Vet et al. 1999; Nagan and Zoeller 2001).