In a previous paper (1) the inactivation of catalase by heat at different pH was studied. It was discovered that the heat inactivation depends upon the hydrogen ion concentration of the enzyme solution which affects both the velocity and the extent of the reaction. It was also found there that 65” was the critical temperature for the enzyme preparation since at this temperature the catalase was...

IN a previous paper [1] so me effects of treatment with trypsin on the growth and the energy metabolism of mesenchyma tissue in culture were described. It has been shown that damage by trypsin tends to slow down the growth and to depress the respiration of the tissue. The aim was now to examine to what extent tissue in culture will suffer damage from excessive 01' deficient hydrogen ion concent...

Studies were made with time-lapse motion pictures of the reactions of cells in culture to changes in their environment. The concentrations of H(+), HCO(3) (-)and CO(2) in the medium were altered in such a way that each, in turn, could be maintained constant while the others were varied. Observations were made on the shape of the cells, their activity, and their relation to the substratum. Chara...

In a previous paper (1) the inactivation of catalase by heat at different pH was studied. It was discovered that the heat inactivation depends upon the hydrogen ion concentration of the enzyme solution which affects both the velocity and the extent of the reaction. It was also found there that 65” was the critical temperature for the enzyme preparation since at this temperature the catalase was...

IN the course of an investigation into the value of the glass electrode as a means of making continuous records of the hydrogen ion concentration of circulating blood, it was found, in the preliminary experiments in which estimations were made on single samples, that there were several sources of serious error. The difficulties encountered in devising a satisfactory apparatus for measuring glas...

The marked effect which minute amounts of tissue and of yeast extracts have upon the growth of organisms has long been known, but the chemical composition of these organic substances, one or more of which are required by many organisms for growth, has been determined only during the past ten years. The determination of the chemical structure of these substances has made it possible to grow many...

1. Actively growing pneumococci produce acid at such a rate that change in the pH of the medium parallels change in rate of growth. 2. The death of the pneumococci is not followed by change in the reaction. 3. Acidification during growth in beef infusion media proceeds until a pH of about 7 is reached. At this point growth stops. The increase in hydrogen ion concentration is not the only origin...

In the first paper of this series (1) a model for microheterogeneity of plasma albumins was presented together with some critical evidence in support of its adoption. According to this model plasma albumin consists of a very large number of similar molecular species. The N-F transition of the protein as observed by electrophoresis, solubility, optical rotatory dispersion, and other methods is a...

A convenient and accurate method is described for the electrometric determination of the hydrogen ion concentration of small amounts of fluid (0.015 to 0.020 cc.). The suitability of such a method for work on insect blood and body fluids is particularly pointed out.

Deposition of chloride ions in the surface layer of concrete is investigated in this study. In real concrete structure, chloride ions from the service environment can penetrate into concrete and deposit in the surface layer, to form the boundary condition for further diffusion towards the interior. The deposit amount of chloride ions in the surface layer is normally a function of time, rather t...