Quantitative aspects of metabolic organization: a discussion of concepts

Metabolic organization of individual organisms follows simple quantitative rules that can be understood from basic physical chemical principles. Dynam ic energy budget (DEB) theory identifies these rules, which quantify how in dividuals acquire and use energy and nutrients. The theory provides constra ints on the metabolic organization of subcellular processes. Together with rules for interaction between individuals, it also provides a basis to unde rstand population and ecosystem dynamics. The theory, therefore, links vari ous levels of biological organization. It applies to all species of organis ms and offers explanations for body-size scaling relationships of natural h istory parameters that are otherwise difficult to understand. A considerabl e number of popular empirical models turn out to be special cases of the DE B model, or very close numerical approximations. Strong and weak homeostasi s and the partition-ability of reserve kinetics are cornerstones of the the ory and essential for understanding the evolution of metabolic organization .