The primary task that the authors will attempt to achieve in this manual is to present the basic principles of Biochemistry itself. These principles are based upon the huge amount of already accumulated knowledge, the experimental data, and its comprehensive consideration and generalisation. Therefore, only some carefully selected parts of this material are given in this manual which aim to both support and illustrate the general statements presented, and to supply the reader with the practical knowledge most essential for a systematic exposition of the biochemical material and for further study of other biological disciplines.