ABSTRACT
Overall, bioenergetics is concerned by chemical reactions carried out in particular conditions which are those of the life. In brief, they are biochemical reactions. They, of course, involve the participation of chemical species which may appear or disappear during the studied transformation. As a result, considering closed systems only, as it has been the case up to now, is not sufficient for the study of bioenergetics. The theory which has been developed so far is only applicable to closed systems. Recall that closed systems are those which can exchange energy (heat and work) with the environment, but the transfer of matter through their boundaries is impossible. Open systems are those which can exchange both energy and matter with their surroundings.
