| Comments |
P.83 bottom paragraph: "To obtain an order of magnitude of the energy consumption for active ion transport in plants, it is assumed on the basis of the information of Table 2, that active fluxes amount to 1-2×10^-12 mol/cm^2 plasmalemma/sec. Furthermore, it is assumed that a considerable fraction of this flux represents coupled active transport, and that per active ion movement the energy of 1 ATP molecule is required. Cells with dimensions of 40×40×40 µm have about 1-2×10^4 cm^2 plasmalemma/g dry weight. From such numbers it follows that maintenance of these fluxes consumes about 4 mg glucose/g dry weight/day. In young and small cells this value may be larger, while in large parenchyma cells it is likely to be lower. Active fluxes across the tonoplast may be roughly similar to those across the plasmalemma (Table 2)." |