ATPrendement

ATPrendement is a theoretical metric used in discussions of cellular metabolism to quantify the efficiency of ATP production relative to substrate input under defined conditions. The concept integrates ATP yield from glycolysis, the citric acid cycle, and oxidative phosphorylation, while accounting for energy costs associated with substrate transport and maintenance.

Etymology and origins: The term blends ATP with rendement, the French word for yield, highlighting its focus on energetic efficiency in metabolism. It has appeared in theoretical writings and in some metabolic models as a shorthand for comparing pathways or organisms, particularly in discussions of energy economy and bioprocess optimization.

Definition and calculation: ATPrendement is not standardized. It is commonly described as net ATP produced per mole of substrate consumed, or as the ratio of ATP produced to energy expended for cellular maintenance and substrate processing in a defined system. Calculations can vary by whether maintenance costs are included, how proton motive force is treated, and which energy sinks are accounted for.

Applications and relevance: Researchers use the metric to compare metabolic efficiency under different environmental conditions, genetic modifications, or substrates; in metabolic engineering to optimize yield; and in ecological or industrial contexts to assess energy use in microbial or cellular systems. It can inform decisions in bioprocess design and strain selection.

Limitations and criticism: The lack of a universal definition and the dependence on organism, substrate, and conditions limit cross-study comparability. ATPrendement is largely a modeling or theoretical construct rather than a universally adopted, standardized measurement, and practical applications rely on transparent assumptions and consistent methodologies.

See also: ATP yield, cellular respiration, glycolysis, Krebs cycle, oxidative phosphorylation, metabolic efficiency.