Diagram of the chloroplast pump model with representative Ci (inorganic carbon) concentrations

Range Table - link
Organism Diatom Phaeodactylum tricornutum
Reference Hopkinson, B.M., 2014. A chloroplast pump model for the CO2 concentrating mechanism in the diatom Phaeodactylum tricornutum. Photosynthesis research 121, 223-233 p.224 figure 1
Primary Source Hopkinson BM, Dupont CL, Allen AE, Morel FM. Efficiency of the CO2-concentrating mechanism of diatoms. Proc Natl Acad Sci U S A. 2011 Mar 8 108(10):3830-7. doi: 10.1073/pnas.1018062108PubMed ID21321195
Method Primary source abstract: "[Investigators] used mass spectrometric measurements of passive and active cellular carbon fluxes and model simulations of these fluxes to better understand the stoichiometric and energetic efficiency and the physiological architecture of the diatom CCM [CO2 concentrating mechanism]."
Comments P.226 right column bottom paragraph: "To test the consistency of the chloroplast pump model of the P. tricornutum CCM with data, a numerical box model representing important intracellular compartments (cytoplasm, chloroplast stroma, and pyrenoid) and Ci fluxes was developed (Fig. 1). The ability or inability of the model to explain Ci [inorganic carbon] uptake and photosynthesis as a function of extracellular Ci, subject to literature constraints on CA [carbonic anhydrase] activity, intracellular pH, and RubisCO content was found to be especially informative." P.224 left column 3rd paragraph: "Based on these findings, [investigators] proposed a model for the P. tricornutum CCM, here termed the “chloroplast pump” model (primary source). In this model, the major driving force for the CCM is active transport of HCO3 − into the chloroplast, which generates two important CO2 gradients: (1) the elevation of CO2 around RubisCO over the extracellular concentration and (2) the CO2 deficit in the cytoplasm relative to the extracellular concentration, which drives diffusive CO2 influx (Fig. 1, primary source)." See note beneath diagram
Entered by Uri M
ID 116865