Sample abstract: Single student project, 6th grade
UNDER WHAT CONDITIONS DOES YEAST RESPIRE THE MOST RAPIDLY? Stephen Herr, and Shirley Deedon (teacher). Valley Presbyterian School, 9200 N. Haksell Ave. North Hills, CA 91343
Experiments were developed to determine the optimal conditions for yeast respiration as measured by the production of carbon dioxide that was collected by water displacement. Flasks containing 2.0 grams of baker's yeast, Saccharomyces cereviseae, and a constant amount of sucrose, were placed in water baths at different temperatures from 10 to 70 C. It was determined that yeast respired best at approximately 45 C. When the experiment was repeated at 45 C using sugar concentrations from 0 to 30% (by weight), it was determined that yeast respired most rapidly in a 24% sucrose solution. Keeping the temperature at 45 C, yeast was put in 24% sugar solutions ranging from pH 1 to 12 and it was found that yeast respired most rapidly at pH 7. It was determined that the addition of salt reduced the respiration rate when temperature, sugar concentration and pH were kept constant at optimal values. When Nutra-sweet was substituted for sucrose the respiration rate decreased indicating that yeast respires more rapidly in natural sugar. It was concluded that baker's yeast respires most rapidly at 45 C, in 24% sucrose solution, at a pH of 7, with no additional salt.
Sample abstract: Half-class project, high school
IMPLEMENTING THE MICROBIAL LAVA LAMP AS A SCIENTIFIC TEST INSTRUMENT IN A HIGH SCHOOL CLASSROOM. A. Ben-Blkanah, E. Crayton, A. Donanville, L. Goras, M. Hamzavi, Y. Kakan. M. Niknar, T. Ortega, N. Pezeshki, J. Forter, N. Sarouha, J Schuller, J. Vincent, J. Zaman, and D. Gaughen (teacher). Taft High School, 5461 Winnetka Ave., Woodland Hills, CA 91346
The purpose of this study was to demonstrate the microbial lava lamp as a useful test instrument in high school science classes. The microbial lava lamp was developed by microbiologists Alan King and Paul Tomasek. The lamp is constructed from colorful yeast beads encapsulated in a glass/alginate mixture. When the beads are placed in an enclosed container or sugar and water, they will slowly rise to the surface of the partially filled container, pause momentarily, then slowly descend to the bottom. The motion of the beads repeats until all of the sugar is metabolized by the yeast. The slow, continuous movement of the colored beads is reminiscent of the 1960's lava lamps. Quantitative measurement of this metabolism is recorded by carbon dioxide bubble counters (fermenters) placed on top of the containers., usually two-liter plastic bottles. Students were able to implement the King-Tomasek protocol, construct the lamp, and measure optimal sugar (sucrose) concentrations. Sugar concentrations in different containers were tagged by different colored yeast beads with uncolored beads given to the control of no sugar or 0% concentration. Students evaluated carbon dioxide productivity by (a) maximum bubble count, and (b) longevity of output. Bubble counts were recorded on a daily basis for a number of days. A 20% (by weight) sugar concentration was found to be optimal by the students according to productivity criteria. This optimum can serve as a control for further student experimentation on yeast-sugar (or sweetener) metabolism.
Sample abstract: Entire Class Project, high school biology class
THE EFFECT OF CALCIUM CONCENTRATION ON SEA URCHIN FERTILIZATION. R.Aden. J.Adams, R.Aghopogli, P.Aliabadi. A.Antonio, A.Arpiza, D.Ayala, T. Babila, M. Baumgarten, I.Baumgartner, K.Bevington. M.Blank, R.Braff, J. Choenchavalit. K.Cilengir,S. Contreras, D.Cortes, S. Crawford, Y.Cruz, L . Darling, B.DeShields, N. Diego, S .Ebneyamin, D.Farag, M.Fernandez, D.Flax, M.Flores, J.Franco, D.Garcia, A.Gest, D.Ginsburg, C. Gonzalez, A.Green-Dove, R.Griffin, V.Guerra, D.Haft, G.Hernandez, S.Holt, E.Horwitz, A.Hutterer, C. Jaramillo, A.Johnson, D.Jones, C.Kass, F.Landis. E.Lemus, D.Lenvin, H. Lopez, M.Lopez, O.Luis, S.Mahboobian, B. Martinez, J. McDonald, I.McFields, C.McGrath. B. Mitchell, D. Morgan, K. Morris, C.Munoz, R.Nagler, K.Narayan, W.Noor, J. Olmedo, A. Ordonez-Chu, C.Page, L.Perez, D.Phillips, K.Pinto, L.Pullan, B. Rabinowitz, R.Ramos, J. Reivitis, D.Reynoso, M.Rios, G.Rosenfeld, R.Rosenstein, R.Salim, J.Schkud, J.Schlierman, A.Siegel. S.Taren, L.Tistaert, A.Valenzuela, K.Vashkevich, A.Vasquez, M.Viault, J.Volz, R. White. K.Wick, C.Wilson, N.Wu, N.Wyman, T.Yuki, and P.Mayerson. (teacher). Santa Monica High School, 601 Pico Blvd., Santa Monica, CA. 90405.
PURPOSE: To examine the effect of calcium on sea urchin fertilization. HYPOTHESIS: An increase in calcium ion concentration will result in an increased amount of fertilization PROCEDURE: Male and female sea urchins of the species S. purpuratus were injected with 0.5 M KCI and the eggs and sperm were collected in plastic tubes and kept on ice for 22-26 hours. Sperm were kept concentrated and eggs were placed in Artificial Sea Water (ASW) (pH 8.0) containing 9.25mM calcium. One drop of egg suspension was put onto each slide. Each student group followed one of three protocols: ( l ) ego suspension + 2 drops of ASW containing calcium, (2) egg suspension + 1 drop ASW with Ca and l drop ASW without Ca.(3) egg suspension + 2 drops ASW without calcium. All groups counted the eggs in one field of view on low power (100x) and then added one drop of diluted sperm suspension in ASW with Ca. Each student counted the total number of eggs in one field of view and the number of fertilized eggs. Fertilized eggs can be easily identified by their fertilization membrane which gives each egg a halo. RESULTS: Group 1: Eggs in artificial sea water containing 100% ASW with 9.25mM calcium showed an average fertilization rate of 76%. Group 2: Eggs diluted to 6.94 mM calcium showed an average of 33% fertilization. Group 3: Eggs diluted in half to 4.625 mM calcium had an average rate of 40.3% fertilization. There was a lot of variation in results. CONCLUSION: Our hypothesis was probably correct. Artificial sea water containing the suggested levels of calcium gives the highest rates of fertilization (variation from 55%-98%) while lower calcium levels gave lower fertilization levels and more variation in results.
Sample abstract: High school Honors biology class, large group project
CONSTRUCTION AND GENOTYPIC/PHENOTYPIC CONFIRMATION OF A DOUBLY ANTIBIOTIC RESISTANT PLASMID. J. G. Anderson, D. Gobrial, J.M. Heisler, D. Hoang, S. Kafai, G.E. Metzenberg, I.A. Moizesch, R.M. Orozco, D.R. Rodstein and J. McLaughlin (teacher). Granada Hills High School, 10535 Zelzah Ave., Granada Hills, CA 91344
The purpose of this study was to construct a plasmid with resistance genes to two different antibiotics using recombinant DNA techniques, and to determine whether plasmids that survived a phenotypic screening process had the expected restriction endonuclease map. Using the Amgen Plasmid Fusion lab protocol, a hybrid plasmid was constructed from pBR325, which contains a chloramphenicol- resistance gene, and pUC18, which contains an ampicillin-resistance gene. Each plasmid was digested with the restriction enzymes Aat II and Sph I which flank the respective antibiotic resistance genes. The restriction enzymes were heat-inactivated, and the digested plasmid samples were mixed and ligated using T4 DNA ligase and ATP. The mixture of plasmids was used to transform competent E. coli cells, and the desired result was selected for on LB plates containing both chloramphenicol and ampicillin. Original research began when transformants that survived the selection were amplified in liquid culture and DNA was extracted (using High Pure Plasmid Isolation Kit by Boehringer-Mannheim) for restriction mapping. Analysis of DNA ( which included gel electrophoresis for characterizing the size of restricted fragments ) revealed the anticipated restriction map using the enzymes Aat II, Sph I, and EcoR I. The EcoR I analysis was particularly revealing since the predicted recombinant plasmid was expected to have EcoR I fragments of different sizes. The results suggest that the phenotypic screening process was successful in eliminating recombinant plasmids lacking both resistance genes from the experiment.
The Journal of Student Research Abstracts welcomes submissions from K-12 teachers that are co-authored by their students. We are now accepting submissions for the 2003 issue (deadline date for receipt of abstracts is Feb. 1, 2003). This journal has been publishing student research for almost a decade. For K-12 students to have a publication under their belts before even getting to college is quite an honor for them, their teachers and their schools. The Journal is fully typeset and published by Pearson Education, Boston, Library of Congress Number ISBN 0-536-63042-9.