Abstract mathematical molecular biology

The tremendous complexity of even the simplest living unit makes a correct theoretical guess as to its mechanism very difficult. It is therefore suggested that, following the example of the physical sciences, a number of purely abstract cases in molecular biology be studied mathematically at first. Subsequent comparison of the different conclusions of such an abstract theory with available data would enable us to decide which of the conceivable situations are likely to occur in reality. As a first step toward such a study the problem of the minimal size of a living unit is studied. Usually the minimal size is considered to be determined by information-theoretical requirements. It is shown that the minimal size may have a very different origin. It may be determined by the possibility that too small a system, even though performing all necessary biological functions, may not be viable unless it is a member of a large group of other similar systems. This approach is developed both from a metric and from a relational point of view. Some relational characteristics of systems of reactions which possess the elementary metabolic properties of organisms are studied.