Illinois Junior Academy of Science - Yearbook (Urbana, IL)

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The Effect of L-Cysteine Hydrochloride Upon a Penicillium Fungus PAUL RAPP Schurz High School Chicago t-cymu.m.aunm ppp V Efflllllhllfllll The purpose of this experiment program was to determine the effect of animo acid concentrations upon a Penicillium fungus. The fungus employed is common to exposed pine- apple. In the pilot study twenty-two amino acids were tested. The results generally fell into three categories: ill no effect 127 the fungus continued to grow but in a distorted form Q31 the mold did not grow. Obviously the third type of result is the most important. There was only one amino acid in this group: L-Cysteine I-Iydrochloride. Further experiments hoped to determine if the result in the pilot study could be employed practically. To ac- complish this it was necessary to grow cultures containing various concentrations of amino acid treatment. The experiments bore out the results of the pilot study. L-Cysteine Hydrochloride does indeed retard the growth of the Penicillium fungus employed. I found that a treatment of .04997g.!ml. lgrams of L-Cysteine Hydrochloride crystal dry weight to ml. of culturel was able to control the fungus for at least 120 hours. It was alsd found that a treatment of 0.9286g!.ml. controlled the growth for sixty days or more. Other research in this area by others substantiated my con- clusions. It is believed that the L-Cysteine Hydrochloride treatment interfers with the cell division of the fungus. Determination of Percent Dissociation of Solutions by Concluctance RICHARD MUELLER CRAIG ZASTERA 1:5- NC! ..'i'Z'!.'21 '.L1m'- of WDIUII cntolllli In this experiment, the conductance of a solution was used to determine its percent dissociation. This procedure is dependent on the fact that conductance is proportional to the number of ions in solution. A meter unit applied an appropriate voltage to a solution in a conductance cell equipped with platinum electrodes. This unit measured the voltage and current in the cell from which resistance was found by Ohn1's Law. , Specific conductance is the reciprocal of the resistance through one cubic centimeter of solution. A cell constant, dependent on the dimensions of the cell. converted the re- sistance through our cell to this standard. When specific conductance was multiplied by the number of cubic centi- meters required to obtain one normal of solute, equivalent conductance -- that of one gram equivalent of solute - was obtained. This was plotted against the square root of con- centration and extrapolated to determine the conductance at infinite dilution - when the solute is completely dis- sociated. Comparing this value to the conductance at each concentration gives the percent dissociation. There are two basic factors which influence conductance- mobility and percent dissociation. With strong electrolytes, the former is the predominate factor, while in weak electro- lytes, the later is more important. In general, the conduct- aknce decreases with concentration due to the proximity of t eions.

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been shaken with apple juice, a residue was left. When added to normal apple juice it was found that the mixture was at least 11 time more resistant to mold tfrom a time standpointl than plain apple juice. Benzene is a very general solvent and it would be desirable to dissolve the mold resisting benzene extract in a less gen- eral solvent. Methanol was tried. Part of the extract was soluble in methanol and part was not. An experiment showed that the methanol soluble part acted as the resistance factor. In conjunction with the experiments infra-red and ultra- violet spectograms were made. These showed that the com- poundfsl acting as the resistance factor must be an organic aliphatic moleculetsl. Also, addition proof that the methanol soluble part of the benzene extract acted as the resistance factor was obtained. It is hoped that the resistance factor can be completely isolated and identified. It may find a use as an anti-fungal agen . i l l f Q.. lmmunoelectrophoresis in Animal Serum LENORE POLLAR'D l8l Sacred Heart School Hubbard Woods Sponsor: Vera R. Madgey v :' Q: .fi After working with animal serums, I found that dogs have more gamma-globulin in their blood than do cats, and that chickens have more albumin than dogs. My work of analyzing blood serums would seem to in- dicate that this technique holds promise for diagnosing blood diseases in animals. The Effects ot Fluoride on Liver Enzymes AN-NE LONERGAN Boylan High School Rockford . 'wtf' , .... N-f-- ' .,- , The purpose of this science project was to determine the pathological effects of fluoride. To be specific, fluoride is supposedly an enzyme inhibitor. So by maintaining mice on different concentrations of fluoridated water and then by removing their livers and performing the transaminase enzyme test, it was hoped that the effects of fluoride on liver enzymes could be determined. It was found that, first of all, fluoride affected the weight, size, and coloration of the livers. And secondly it apparently, gradually increased the enzyme activity instead of inhibiting it. A secondary purpose was to see if the transaminase test could be run on the actual liver homogenate instead of the usual blood serum. This was determined by homogenating each liver to obtain a thick serum. First, different amounts of substrate were reacted with the homogenate and tested. Then by serial dilutions the enzyme concentration of the homogenate was decteased with saline. The 1f100 dilution was found to be satisfactory. So a liver homogenate may be used instead of a blood serum if it is diluted to the right proportion. The Redox Reaction Between CuClf and Aluminum VICTOR El.lAS Niles North High School When aluminum is immersed in copper sulfate solution, a slow redox reaction occurs in which copper is plated out. The addition of chloride ions speeds the rate at which copper is plated out and causes a gaseous mixture to be released. The purpose of my project is to gain an understanding of this reaction and to determine the role of the chloride ion in the reaction. This information cannot be exactly determined, but by using chemical kinetics, several predic- tions regarding the role of the chloride ion can be considered. In my project I tried to gain enough knowledge of the rate law to be able to hypothesize a reaction mechanism. From this I acquired an enhanced understanding of the role of the chloride ion in the reaction.

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