Active phosphate uptake by Nitella translucens

Abstract

• 1.

  1. Using ³²P as a tracer, phosphate uptake into the giant cells of Nitella translucens has been shown to be a strictly active process. The uptake is light-enhanced and requires a supply of ATP. When non-cyclic electron flow is prevented, the light-dependent process is supported by cyclic photophosphorylation.

• 2.

  2. As it is already known that active Cl⁻ uptake into Nitella translucens is not dependent on ATP but is linked to electron-transfer reactions, there can be no common mechanism for anion transport in these cells.

• 3.

  3. Measurements of the relative amounts of ³²P in the cytoplasm and vacuole have shown that the cytoplasm contains nearly all the organic phosphate, while a large pool of inorganic phosphate may be formed in the vacuole.