Primary metabolites are involved in normal growth and development and are often part of metabolic pathways necessary for survival. These include small, polar metabolites like amino acids, nucleic acids, sugars and small organic acids.
Secondary metabolites are usually not essential for survival but can provide evolutionary advantages. Secondary metabolites are typically non-polar.
Lipids metabolites are formed during lipid metabolism, the synthesis and degradation of lipids in cells. Lipids play critical roles in cell membrane structure, molecular signaling and cellular responses to environmental conditions. Lipids are also precursors for biofuels or for the formation of secondary metabolites. Lipid metabolites can serve as biomarkers for health and disease and interactions between host and pathogen. Lipid metabolites can serve as messengers to control metabolism.