Lom ia ae | ©. ts , III - BIOLOGY AND MEDICINE Weapons Test Activities Radiation telemetering - Operation CASTLE (Gasca - tion with the coming test operations in the Pacific, mart c>tpation| of di-vision personnel has been requested by Joint Task Force 7 in orderJ to make use of AEC's radiological telemetering equipment. The telemetering} system, which was first employed in the 1953 spring test series, is to be fised at. fixed Locations in areas of expected high radioactive contaminati that radiation intensity measurements may be supplied safely and Such data are necessary after a detonation in order to determine liest time of safe entry for recovery parties at the locations. e Research Activities (UNCLASSIFIED) Effect of toxic substances on celis. Since the effects off toxic materials on body tissue differ, it is necessary to understand th— mechanism of action of these poisons on the body tissues at the cellufar level. A unique study, which has been under way at the University of Roghester Atomic Energy Project, is concerned with the intimate dependence Pf the cell's metabolic activities on the special properties of the cel¥ surface. This work indicates, at least in the systems studied, that some gf the cell's most essential bio-chemical conversions take place withou} the entrance of the ingredients into the interior of the cell. Evid@gntly, these conversions are accomplished by action of enzymes which arg fixed leaving the cell and without the entry of the substances upon w act. Most of the work on this project has been with yeast cel and their turnover of organic phosphates, compounds which are of primary gnificance in the metabolism of carbohydrates. Uranium ions form a comple# with certain groups (probably polyphosphates) on the surface of the yeadt cells, and do not pass through the surface. Yeast so complexed with anium fails to carry out the initial steps in sugar metabolism. Molybdate dnd tungstate in low concentrations similarly inhibit surface phosphatagBes and prevent the splitting and utilization of sugar phosphates in thf medium. Analysis of the cell potassium, and study of the potassium-hydrpbgen exchange across the surface, have shown also that the stimulationj of fermen- tation by the potassium ion involves only the most peripheral yers of the cell. This stimulation does not depend on any change in t internal potassium level or the rate of its exchange, but only on the external potassium-ion and hydrogen-ion concentrations. The most ready Finterpretation of these observations is that the phcosphohexokinase react on (initial step in glucose fermentation) actually takes piace in the exte nal medium immediately in contact with the enzyme at the ceil surface. E periments in progress indicate that a similar arrangerse:.. prevails for a number of 8 the subsequent steps in the carbohydrate wetabclic system. App ication of DOE ARCHIVES