This course will cover the fundamentals of organic geochemistry, which is the discipline that studies the origin, conversion and fate of organic matter on Earth, and attempts to reconstruct the impact and processes that the biosphere had on the Earth system. In lectures we will cover (amongst other themes) carbon fixation and bioproductivity, aspects of lipid biosynthesis, biomass burial and the global carbon cycle, the formation and composition of fossil fuels, paleoclimate reconstructions, environmental geochemistry and what ancient molecules tell us about the evolution of life on Earth. In the practical part of the course, we will gain hands-on experience by processing rock samples, extracting and simplifying their molecular organic inventory and analyzing the latter using gas chromatography and mass spectrometry, followed by interpretation of fossil biomarker molecules.