4. Origin of life
Let's consider the fourth condition of realisation of model of charges transfer: Thermodynamic reversibility of charge transfer on SCIHB. Feature of the mechanism of charge transfer on SCIHB is possibility of their only unitary passage on system of bonds in one direction. However this process can take place successful in the opposite direction. To it can promote identity of donors (D1=D2) and acceptors (A1=A2), participating in reception of charges in direct and return directions, and also symmetry of donor and acceptor sites of SCIHB. Symmetry of SCIHB can be created on the basis of the identical substructures laid symmetrically under the relation to each other. At molecular level it is shown that the majority of biostructures consists of identical subunits, and their number, as a rule, is even.
Whether it is possible on the basis of requirement reversibility of charge transfer to present an origin of live beings? It appears it is possible, but for this purpose it is necessary to take into consideration one more theory. It is considered, that the science has not given till now the unequivocal answer to a question on a life origin. However, actually the answer is found for a long time already, though has not received sufficient popularity. It is a question of the theory evolutionary catalysis, developed by prof. A.P. Rudenko . In a short form it is stated in the book .
Within the limits of the evolutionary catalysis theory object of chemical evolution in which course there were biosystems, is the elementary opened catalytic system (EOCS), i.e. complete set of the catalyst, reacting substances and products in all phases catalytic stages, connected in a uniform kinetic continuum. Such objects which basis of existence is basic process, have passed in process of long evolution and selection the way which has led to occurrence of biosystems.
A.P. Rudenko's theory describes the general laws of chemical evolution, not concretising the mechanism of carrying over of charges which can underlie realization of basic reaction. However at transition directly to an origin of biosystems it is necessary to consider the concrete mechanism of carrying over of charges in them too.
As we saw, the mechanism of charges transfer on SCIHB can be realised only under condition of symmetric subunit organizations of structures. In book  prebiological structures with such organization are named EDOCS (elementary duplicated opened catalytic systems). Subunit structure of EDOCS creates a condition for their interaction at population level and exchange by subunits therefore structures with higher symmetry and higher capacity of basic reaction can be formed. In turn, it increases duration of their existence and possibility of participation in the subsequent recombination. Such mechanism of recombination and selection of EDOCS on a maximum of basic process carries the name of population-template model as passes at level of the population which is simultaneously a template of selection too.
Transition to Section 5. A model hypothetical example