Description

In order to give, in terms of physical chemistry, an explanation of the so specific behavior of living systems it is necessary, if not sufficient, to analyse the mechanisms which are acting inside the living cell. These mecanisms involve the actions of fundamental macromolecules, the proteins and the nucleic acids, which are universal constituents of living matter. The structure of these chain molecules is described and it is shown that they behave like small molecular machines, which can play the role of constituents in a cybernetic assembly. Despite the progress of our knowledge in this field, it is concluded that we are still very far away from even an elementary knowledge of Life but that, nevertheless, the study of the biomacromolecules considerably enriches our views on macromolecular physicochemical systems. Resume Afin de pouvoir interpreter les caracteres des systemes vivants en termes de physicochimie, ilest necessaire - sinon suffisant - de connahre les meca- nismes eIementaires dont la cellule vivante est le siege. Ces mecanismes eIementaires sont portes par des macromolecules, les proteines et les acides nucleiques, constituants universels de la matiere vi- vante. On decrit la structure de ces chaines moleculaires si speciales et on montre qu'elles se conduisent comme de petites machines elementaires, pouvant agir comme des composants dans une cybernetique d'ensemble.