This textbook is designed for students of biology, molecular biology, ecology,medicine, agriculture, forestry and other professions where the knowledge of organic chemistry plays an important role. The work may also be of interest to non-professionals, as well as to teachers in high schools. The book consists of 13 chapters that cover the essentials of organic chemistry, including - basic principles of structure and constitution of organic compounds, - the elements of the nomenclature, - the concepts of the nature of chemical bond, - introductions in NMR and IR spectroscopy, - the concepts...