An action spectrum apparatus

An instrument is described which is capable of measuring the action spectrum of the removal of CO inhibition of respiration by light. In the method employed here, a cell suspension in a CO-O₂ atmosphere is alternately exposed to two wavelengths of light. Their photochemical effects are balanced using an 0₂ electrode as the null detector. The light intensities at the balance points from a series of wavelength pairs are used to determine the ratios of the extinction coefficients of the CO - oxidase complex, at the various wavelengths, to the extinction coefficient at a standard wavelength. An action spectrum for Bakers yeast is shown.Science, Faculty ofPhysics and Astronomy, Department ofGraduat