Lecture, 3 credit, 3 hours per week. This course introduces isotopic distributions in different natural systems and the physical, chemical, and biological processes that underlie such distributions, variations, and changes. Students will also be able to apply the fundamentals to the studies of biosynthesis of organic molecules, metabolism, environmental and climate reconstruction. The course also serves as a precursor to advanced understanding and applications of isotope systematics in science and especially in marine science studies, as well as ability to obtain the isotopic signals and make use of these signals to resolve scientific problems.