The course will deal with chemical reactions proceeding in the living matter as a parallel to the reactions known from the organic chemistry laboratory. The following topics will be covered: (1) Enzyme-catalyzed nucleophilic substitution, electrophilic addition, Michael addition, elimination, aldol reaction, Claisen condensations, amination-deamination, molecular rearrangements, and domino reactions, etc. (2) Stereochemistry of the individual processes and isotopic labelling as a tool for elucidation of reaction mechanisms. (3) The role of selected biomolecules in living organisms (4) Biosynthesis of selected biomolecules and the methods for its artificial control with a view of development of new medicinal drugs. (5) Mechanism of action of selected medicinal drugs and poisons (e.g., novichok) at a molecular level and the application of this knowledge for the development of new drugs. Knowledge of standard organic chemistry and good arrow-pushing skills are a prerequisite. Passing a basic biochemistry course before attending this course is not required but would desirable. Complete course materials will be handed out as a supplement to the lectures and tutorials.