Organisms can be classified as phototroph, chemorganotroph and chemolithotroph, according to the way they obtain energy Oxygen or any other molecule can be used as electron acceptor as long as it exhibits the same function. In spite of the metabolic differences, these organisms are governed by a basic physical principle: substrates are used to generate a flow of electrons thermodynamically favorable, where the produced energy can be used for multiple functions. In this sense, it can be said that organisms are true voltaic batteries. This type of assumptions have made a considerable advance in the biochemical conceptual structure. However, the educational system has not change at the same time. The present discussion demonstrates the importance of re-writing biochemistry text books in order to capture the new perceptions that emerge from the discoveries of new types of life considered unimaginable until recently,
