Electromagnetic (EM) or thermal stress (HS) result in altered patterns of biosynthesis that are characterized by new and missing proteins. With both EM and HS stresses, proportionally more new low molecular weight (MW) proteins are synthesized and the distribution of their mass is skewed to lower molecular weights. These observations suggest that the new proteins could be the result of an interruption (i.e., early termination) of biosynthesis. The missing proteins are distributed as the control proteins in unexposed samples and are largely negative for all molecular weights. In contrast, the new proteins are distributed symmetrically with regard to 6.0 < p I < 6.5, and smaller molecules are more highly charged, both positively and negatively. The number of new proteins divided by the amount of new protein, a measure of diversity of product, increases with the frequency or repeat rate of the EM stimulation while the number of missing proteins decreases. These data are in accord with the electrochemical model in that interference should increase with both the frequency of the EM and the charge on the molecules, and result in smaller polypeptides than in the control cells. The results on HS appear to follow the same pattern as the EM experiments, indicating that electrochemical properties affect the responses to thermal stimuli.