Fractionation of carbon isotopes in oxygenic photosynthesis the bundle sheath cells. Different forms of CCM in phytoplankton include the active uptake of bicarbonate and CO through the cell membrane, the active transport of inorganic carbon from the cellular membrane to the chloroplasts, and active, unidirectional conversion of CO to bicarbonate. The parameters affecting C fractionation in phytoplankton contribute to "δ"C values between -18 to -25‰. Fractionation of carbon isotopes in oxygenic photosynthesis Photosynthesis converts carbon dioxide to carbohydrates via several metabolic pathways that provide energy to an organism and preferentially react with certain stable isotopes of carbon. The selective enrichment of one stable isotope over another creates
Fractionation of carbon isotopes in oxygenic photosynthesis processes that selectively use one carbon isotope over the other, or "fractionate" carbon through kinetic or thermodynamic effects. Oxygenic photosynthesis takes place in plants and microorganisms through different chemical pathways, so various forms of organic material reflect different ratios of C isotopes. Understanding these variations in carbon fractionation across species is applied in isotope geochemistry and ecological isotope studies to understand biochemical processes, establish food chains, or model the carbon cycle through geological time. Carbon isotope fractionations are expressed in using delta notation of "δ"C ("delta thirteen C"), which is reported in parts per thousand (per mille, ‰). "δ"C is