Figure 7.

Activity of thioredoxine reductase during the cell cycle in synchronous cultures of Scenedesmus quadricauda. Activity of thioredoxine reductase during the cell cycle in synchronous cultures of the wild type (A), selenite resistant (B), selenate resistant (C) and selenite/selenate resistant (D) strains of Scenedesmus quadricauda grown in the presence of 50 mg Se × l^-1 of selenite or selenate or selenite+selenate. A specific activity of the TR is expressed as units per mg of cell proteins, where a unit is defined as the amount of enzyme that will cause an absorbance change of 1 at 412 nm using 200 μm NADPH per minute. Data are presented as means ± S.D. of triplicate experiments.