Contributions to the Energetics of Animal Growth
F. KRUGER
Abstract
It is shown that the mathematical formulation of PUTTER-BERTALANFFY of the
anabolism-catabolism concept of growth has to be accomplished by a third term
connecting the energetic output of anabolism with the production of living
matter. This third term leads to the concept of the "Struktur-Energie" and
opens methods for its numerical evaluation. The "Struktur-Energie" represents a positive entropy. Some examples are given for the application of the
concept of the "Struktur-Energie".
Introduction
It is a well known fact that growth not only consists of the addition of
new matter to the existing organism, but that there are always processes
which destroy a part of the living structure. Growth represents an equilibrium between these building processes which we call anabolism and the
destroying processes which we call catabolism.
The matter for the organization of new body substances is delivered by
the food, but the organization of this new living matter not only represents
chemical problems but also important energetic problems, which have not
been dealt with thoroughly until now.
Energy is a physical concept. If we wish to understand and to describe
the part played by energy in the course of growth we need a mathematical
model for the description of the quantitative relations during growth.
There are many proposals for the mathematical description of growth, but
most of them are applicable only to special cases.
Nearly half a century ago PUTTER [11] introduced into the mathematical
description of growth the concept of the equilibrium between anabolism
and catabolism. He assumed that the processes which build up new matter
approximately follow the surface rule and that the catabolic processes are
proportional to weight. This assumption can be supported by many experimental facts.
In 1934 Von BERTALANFFY [1] - without knowledge of PUTTER'S
paper - started with the same concept and arrived principally at the same
8 3. Symp. Quant. Bioi.
F. KRUGER
Abstract
It is shown that the mathematical formulation of PUTTER-BERTALANFFY of the
anabolism-catabolism concept of growth has to be accomplished by a third term
connecting the energetic output of anabolism with the production of living
matter. This third term leads to the concept of the "Struktur-Energie" and
opens methods for its numerical evaluation. The "Struktur-Energie" represents a positive entropy. Some examples are given for the application of the
concept of the "Struktur-Energie".
Introduction
It is a well known fact that growth not only consists of the addition of
new matter to the existing organism, but that there are always processes
which destroy a part of the living structure. Growth represents an equilibrium between these building processes which we call anabolism and the
destroying processes which we call catabolism.
The matter for the organization of new body substances is delivered by
the food, but the organization of this new living matter not only represents
chemical problems but also important energetic problems, which have not
been dealt with thoroughly until now.
Energy is a physical concept. If we wish to understand and to describe
the part played by energy in the course of growth we need a mathematical
model for the description of the quantitative relations during growth.
There are many proposals for the mathematical description of growth, but
most of them are applicable only to special cases.
Nearly half a century ago PUTTER [11] introduced into the mathematical
description of growth the concept of the equilibrium between anabolism
and catabolism. He assumed that the processes which build up new matter
approximately follow the surface rule and that the catabolic processes are
proportional to weight. This assumption can be supported by many experimental facts.
In 1934 Von BERTALANFFY [1] - without knowledge of PUTTER'S
paper - started with the same concept and arrived principally at the same
8 3. Symp. Quant. Bioi.