The effect of the peroxide concentration and other factors on the decomposition of hydrogen peroxide by catalase.

graphic analysis detected traces of Cr+++ in all organs, with most in thyroid and spleen. The relationship.between the activation by Mn++ and that by Mg++ +Cr++++HDP is curious. The variability in the ratio of these two activities (see Table 6) at first indicated that two different enzymes might be concemed, but the absence of any marked change in the ratio during the purification of the enzyme, and the variability in some other properties of the enzyme between one preparation and the next, suggest that this is not so. Further work on the interrelations between the activations by various metals and combinations is proceeding.