Dynamic energy budget

The Dynamic Energy Budget (DEB) theory aims to identify simple quantitative rules for the organization of metabolism of individual organisms that can be understood from basic first principles. The word "dynamic" refers to the life cycle perspective of the theory, where the budget changes dynamically over time.

Cornerstones of the theory are:

They are essential to understand evolution of metabolic organisation since the origin of life.

DEB theory delineates reserves, as separate from structure. Reserves are synthesized from environmental substrates (food) for use by the metabolism for the purpose of somatic maintenance (including protein turnover, maintenance of concentration gradients across membranes, activity and other types of work), growth (increase of structural mass), maturity maintenance (installation of regulation systems, preparation for reproduction, maintenance of defense systems, such as the immune system), maturation (increase of the state of maturity) and reproduction. This organizational position of reserve creates a rather constant internal chemical environment, with only an indirect coupling with the extra-organismal environment. Reserves as well as structure are taken to be generalised compounds, i.e. mixtures of a large number of compounds, which do not change in composition. The latter requirement is called the strong homeostasis assumption. Polymers (carbohydrates, proteins, ribosomal RNA) and lipids form the main bulk of reserves and of structure.

Some reasons for including reserve are to give an explanation for:

The standard model quantifies the metabolism of isomorphs with 1 reserve and 1 structure that feeds on one type of food with a constant composition. The rules for the standard model for reproducing multicellulars, and modified for dividing unicellulars, are:

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