
Lipids are important biochemicals in organisms where they play roles in energy storage and mobilization, membrane structure, and hormonal regulation of metabolic processes. Due to their wide assortment of organic functional groups, the diverse molecular structures of lipids make them useful for tracing organic matter sources, alterations and transport. Additionally, stable- and radio-carbon isotopic compositions of individual lipid compounds provide a powerful tool for identifying lipid sources and for following carbon flow through ecosystems.