KINETIC MEASUREMENTS OF RHODOPSIN SOLUTIONS DURING INTENSE FLASHES

Kinetic spectroscopy is used to investigate the rate at which metarhodopsin II (meta II) accumulates during (and, in some cases, after) flash photolysis of rhodopsin solutions. This process is studied as a function of flash intensity, temperature, and extracting medium. It is shown that the rate at which meta II accumulates is photo-limited at high temperatures but thermo-limited at low ones. Photoequilibria are shown to exist, under certain circumstances, during the course of a flash. The quantum efficiency of meta II production is shown to be time dependent when intense flashes are used but not when weak flashes are used. It is suggested that kinetic spectroscopy may be useful in investigating the chemical basis of the early receptor potential. © 1968.