Oxygen exchange in ulva using a bare platinum electrode with 4 microsecond saturating light flashes.

Illuminating algae (Ulva species) on a bare platinum electrode with 4 microseconds of saturating light flashes leads to the familiar four-step oscillatory pattern of O(2) exchange. However, it appears that this O(2) exchange is a composite of O(2) evolution and endogenous O(2) uptake in the algae. We have added the O(2) uptake component to the O(2) exchange curve in order to obtain the corrected O(2) evolution flash sequence which shows a similar four-step oscillation as reported previously, but with negligible damping over the first three oscillations.