Palisade cell Palisade cell Palisade cells are plant cells located in leaves, right below the epidermis and cuticle. They are vertically elongated, a different shape from the spongy mesophyll cells beneath them in the leaf. Their chloroplasts absorb a major portion of the light energy used by the leaf. Palisade cells occur in dicotyledonous plants, and also in the net-veined monocots, the Araceae and Dioscoreaceae. Palisade cells contain the largest number of chloroplasts per cell, which makes them the primary site of photosynthesis in the leaves of those plants that contain them, converting the energy in light to the chemical energy of
Fractionation of carbon isotopes in oxygenic photosynthesis RuBisCO-dependent cell growth rate, and the cell geometry and surface area. The use of bicarbonate and carbon concentrating mechanisms in phytoplankton distinguishes the isotopic fractionation from plant photosynthetic pathways. The difference between intracellular and extracellular CO concentrations reflects the CO demand of a phytoplankton cell, which is dependent on its growth rate. The ratio of carbon demand to supply governs the diffusion of CO into the cell, and is negatively correlated with the magnitude of the carbon fractionation by phytoplankton. Combined, these relationships allow the fractionation between CO and phytoplankton biomass to be used to estimate the phytoplankton growth rates.