The first theme is overview on the cell structure, chemical composition, major classes of the biological macromolecules and their functions in cell and organism. Structural organization and biological functions of proteins, as well as enzyme classification, mechanism of enzyme catalyzed reactions will be overviewed. The important chapter is nucleic acids, their biological role and structure, storage and expression of genetic information. One topic includes the role of carbohydrates in nature, their structure and biological functions, as well as lipids, their classification. including membrane lipids and fats. Major metabolic pathways, metabolism of energy and substances, interconnection of metabolic pathways will be reviewed, including metabolism of carbohydrates, lipides, amino acids and nucleotides, regulation of metabolic pathways and signaling systems. One theme deals with the functions of inorganic substances in organism. biological functions of metal ions, ion transport and metalproteins.