Kepinski's model of "information metabolism" is a biological model which is based on the structural organization of the cell and which attempts to describe information processing in analogy to energy metabolism. The terms of control center, information transmission and transformation, energy requirements and boundaries are considered. The principles of this model are explained. The original model is extended by addition of an integrated model of the main states of consciousness and a developmental model of information metabolism. Concepts of protective mechanisms of information metabolism are developed.