[Revised version of the of the concept of digesting mental information].

The concept of information metabolism was introduced by prof. Kepiński at the end of the 1960-ies of the 20th century. The article presents the synthesis of a series of papers aiming to concrete, update and describe in mathematical terms the concept of metabolism of information. Theoretical basis of the model in the context of the theory of information and the main structures and functions of the metabolism of information are presented. These structures are: control centre (nucleus), boundaries (cell membrane), functional structures (endoplasmic reticulum), energy centres (mitochondria), synthesis centres (ribosoms) and elimination centres (lysosoms). At the end, the publications on the mathematical description of the information metabolism model are presented and discussed.