North Central College

Seminar Abstracts
 

Sarah Brady

Alcan Packaging is an international company that develops and produces different flexible plastics that can be used for foods, medicine, and other applications. Besides developing new projects on their own Alcan also directly answers questions posed by their customers. Recently a customer asked Alcan to develop a film that would prevent the photodegradation of their cheese and liquid beverage products. Alcan already had their own UV additives that they could use but they wanted to compare their additives with UV PET films made by two different companies. My research determined which UV films were the most effective and the amount of UV additives that were necessary. I designed an experiment to test each different film on blocks of cheese and pouches of colored liquid beverages. The samples were exposed to UV light and measurements were taken using a Gretag/Macbeth Color-Eye 3100 spectrophotometer to determine how long photodegradation was prevented. In the end it was clear that the UV-PET films from the other manufacturers were more effective than Alcan’s UV additives, however they were far more expensive than the Alcan UV additives. But the final decision was left to Alcan’s customer to decide which route would be best for them.

Jason Karpus

The taste and quality of beer is highly dependent on the types and quantities of the various secondary metabolites present in the beverage. Volatile esters serve as a particularly important secondary metabolite and are produced during the fermentation of sugars. We sought to explore genetic methods capable of altering the metabolomic profile of alcoholic beverages and discover mutations beneficial to the brewing industry. Our research was focused on volatile esters, and we investigated two separate pathways known to control ester synthesis in yeast, which were the RAS/cAMP and FGM pathways. Both pathways have previously been indicated to be important for the synthesis of the alcohol acetyltransferase enzyme Atf1p, an enzyme that catalyzes ester synthesis. Other alcohol acetyltransferase enzymes are hypothesized to be controlled through the same two pathways. While we were unable to complete our work on the RAS/cAMP pathway, we successfully transformed yeast to create mutant strains with either a constitutively on or a constitutively off FGM pathway. The metabolomic fingerprints of these two strains were then compared to that of a wildtype strain using quantitative NMR. Both of our mutant strains displayed lower integrations not only in the chemical shift where esters typically appear, but across the entire spectrum.

Mayra Baltierrez

The application of 1HNMR spectroscopy is used to study the quality of beer in the brewing industry. It can be used to detect any subtle difference in beer production that would detract from the quality of beer. This technique is relatively new to the brewing industry and cost effective. We wanted to research if the type of beer showed a difference using quantitative NMR. A total of 10 beers differing in type (lager and ale) and labeling were analyzed using 1HNMR spectroscopy. Spectra displayed peaks that were located around the regions of 1.0 -1.3 ppm and 3.0- 4.0 ppm. The spectra were then integrated with quantitative NMR using from regions 0.0 - 5.3 ppm. Thin slices around 0.05 ppm were used to integrate and analyze the spectra. Multivariate analysis, a statistical study, will then be applied to the area under the peaks to look for variance among the two different types of beers.

Casey Connolley

The L-isoaspartyl protein carboxyl methyltransferase (PCM) is an enzyme that repairs covalent damage to proteins: spontaneous formation of isoaspartate (isoAsp) from the amino acid aspartate or asparagine. PCM is necessary for maximum survival of Escherichia coli when subjected to environmental stresses. Because these stresses can affect protein folding, we hypothesized that unrepaired isoAsp damage may compromise a protein’s ability to fold into proper conformation or make it more susceptible to denaturing under stress. We predict that a mutant strain of E. coli with a pcm deletion will have more denatured protein after aging and/or exposure to stress than the wild-type strain. We measured amounts of denatured protein by quantitating protein aggregates. The amount of aggregated protein was calculated as a percentage of total protein in the cell. Extracts were heated to quantitate the amount of protein that could be aggregated by heat. We observed a nearly two-fold increase in aggregated protein in cells lacking PCM aged for 5 days and subjected to oxidative stress (paraquat). These results support our hypothesis that there will be more denatured proteins in cells without PCM and suggests that PCM-mediated protein repair is important for maintenance of protein conformation during stress and aging.

Nick Swanson

The Field Museum of Natural History has thousands of artifacts on exhibit, most of which are contained in glass display cases. The cases themselves date back as far as the Columbian Exposition in 1893. Over the years, the Conservationists and Exhibitors have witnessed an unusual problem with the glass in the display cases throughout the Museum. Over time a translucent haze deposits on the inside of the exhibit glass. The rate of development of the haze is as varied as the locations and content of the cases themselves. The goal of this project is to identify the haze and its point of origin in order to assist in maintaining the integrity of the artifacts present and to facilitate the cleaning and maintenance of the cases. Using FT-IR we have been able to identify the main component of the glass haze from one particular case as glycerin. Preliminary analysis of the haze from two other display cases has also been conducted. Although the qualitative, macroscopic appearances of the haze in the display cases are very similar, the physical properties, microscopic appearance, and IR spectra indicate that the chemical composition is different for each of the cases investigated thus far.

Natalie Sisco

Atomic Absorption (AA) Spectrometry is used to measure concentration of elements in solution by absorption of light. The preliminary goal of this research was to bring a newly acquired AA spectrometer (a Varian SpectrAA-20) “on-line” and develop a user-friendly protocol for its use in chemistry courses and research. This included determining some of the performance characteristics of the instrument. In particular, the limits of detection as well as the limit of linearity for copper (Cu) was determined to support the use of the instrument in CHM 142 labs. Further research involved the analysis of iron (Fe). Just like the analysis for copper, the limits of detection and limit of linearity for iron were determined. Subsequently, various water samples around the science center were collected and analyzed to determine the amount of iron present. Results indicate that there is about 20 ppm Fe in tap water from the analytical lab, 1 ppm Fe from the bathroom faucet, and the amount of iron in water from the drinking fountain was below the limit of detection of the instrument.

Dani Kleehammer

Ambystoma tigrinum tigrinum shows intraspecific agonistic behavior as a larva. Agonistic behavior includes the behaviors of the aggressor and the individual that the aggression is towards. Agonistic behavior determines dominance orders between animals. A dominance order minimizes agonistic interactions and therefore increases an individual’s survival. I wanted to see if length of separation time, sex, and visual recognition ability affects intraspecific agonistic behavior in adult A. tigrinum tigrinum. The salamanders were separated by sex and placed into one of two introduction tubs: male or female for one week. Two of the same sex were then put in either one of two tanks on each side of the divider: clear or opaque black dividers. After a being separated for one, two, and three days, tub mates were reintroduced and their behavior was recorded as one of the following: no reaction, retreat, or aggression. Chi squared analyses showed that sex, and visual recognition ability were not significant factors in the intraspecific agonistic behaviors of A. tigrinum tigrinum. Separation time did have a significant effect on no reaction. A. tigrinum tigrinum might use chemoreceptors to recognize each other and not vision, so further studies would test the effect of smell on agonistic behavior.

John Ruskamp

Since lichen species are typically alga partnered with a fungus, they do not have any root structures to gain nutrients from substrate material. Due to their niche, lichens need to be able to gain nutrients from places other than from the ground; primarily from particulate matter in the air. With modern pollutants this can be a disadvantageous situation as they take in poisonous particulates. Some species are able to cope with these particulates while others cannot. By seeing which species is present we should predict what pollution levels are for the area. In this experiment I monitored the pollution levels and lichen diversity at three sites in the Chicago land area. Through rank abundance and total trunk surface area covered, I quantified the lichen species present, and compared that to Pm2.5 data from the Illinois EPA. I found that the lichen diversity decreased as the Pm2.5 value increased in a manner similar to a curve indicating the limiting factor in the ecosystem. However, there was variability in the Pm 2.5 readings and the r values indicate that there is greater than a five percent likelihood that the findings were due to chance.

Cassandra Peterson

Nationally, the sciences are found to be dominated by both males and Caucasians. Studies have indicated science interest in females is higher than that of males in grade 3, but drastically decreases by grade 6. Some of this difference in science interest might be attributed to science education largely focusing on textbooks and definitions. While studies have suggested explanations for this gender difference in science interest, little has been done to examine the difference across cultures. To learn more about these differences in science interest, classrooms in grades 4-6 were each given three exposures to a structured science-inquiry methodology, which encourages collaborative, problem-based learning. These two classrooms were within similar schools containing mainly Caucasian, Hispanic American, and Native American students, which allowed for an evaluation across gender and cultures. Assessments evaluating science interest were given to experimental classrooms and control classrooms in order to quantify the effects of the science-inquiry methodology between genders and the three cultural groups. This alternative method for teaching science showed a significant increase in science interest in females and across Hispanic American and Caucasian American cultures.

Jeremy Smirnov

Quisqualic acid is an excitotoxin that mimics the long-term brain damage observed following ischemia (e.g. stroke.) We hope that understanding the mechanisms of quis excitotoxicity will lead to a better understanding of brain damage caused by ischemia. In our research we are attempting to elucidate the mechanism by which homocysteinesulfinic acid (HCSA) causes a reversal of the quis effect, which is a marked increase in sensitivity to chemicals such as L-2-amino-4-phosphobutanoic acid (AP4) caused by application of L-quisqualic acid. Before quis is added to the neurons, chemicals such as AP4 will not cause a marked depolarization. After quis has been added, however, the response becomes far more pronounced. We hypothesize this is because of a heteroexchange system where quis (which was sequestered during the initial quis exposure) is re-released from a nearby interneuron causing depolarization. A reversal of the quis effect results in AP4 no longer causing depolarization of the membrane. There are three mechanisms via which this reversal could be explained. One is that there is a postsynaptic antagonistic effect - this explanation was shown to be unlikely by the results of previous research. Another hypothesis proposes that quis gets depleted by HCSA. Finally, there is a possibility that HCSA blocks the quis release. To determine the mechanism by which HCSA causes a reversal we used HPLC (High Performance Liquid Chromatography) in an attempt to determine the quis present in brain slices before and after the HCSA is added. We have developed an HPLC protocol which allowed us to separate the amino acids. The amino acids were to be chemically derivatized and separated on a C-18 HPLC column. Rat brain slices were to be tested before and after reversal of the quis effect. If the amount of quis was the same in both samples, it is possible that HCSA blocked the release of quisqualic acid. If less quis was detected, it would be probable that HCSA caused the depletion of quis from the interneuron. Unfortunately, malfunctioning HPLC equipment forced us to modify the protocol to use gas chromatography/mass spectrometry (GC/MS) instead. We were able to successfully identify distinct peaks for the amino acids using GC/MS.

Heather Petersen

A major contributing factor to cellular aging is caused from protein damage. Spontaneous nonenzymatic alterations, i.e. covalent, can cause a protein to change its shape loosing its biological function. To rectify some of these problems the cell has various mechanisms, including enzymes. Spontaneous dehydration of an aspartate protein creates a damaging L-isoaspartyl (isoAsp) isomer. Protein carboxyl methyltransferase (PCM) recognizes this particular damage and with the coupled conversion of S-adenosyl methionine to S-adenosyl homocysteine PCM transfers a methyl group to the isoAsp allowing the isoAsp to return to the aspartate. Without the presence of PCM the isoAsp damage causes local unfolding revealing sites which were then more susceptible to oxidative damage. This was demonstrated by exposing a ∆pcm mutant and wild-type were both exposed to the same oxidative stress. The ∆pcm mutant had more isoAsp damage causing more local unfolding exposing sites of proteins to more oxidative damage then wild-type.

Britni Miller

L-isoaspartyl protein carboxyl methyltransferase (PCM) is a repair protein found in Escherichia coli. The absence of PCM has no apparent effect on exponential growth; but if PCM mutants are under environmental stress, they show significantly decreased viability. I hypothesized PCM mutants lacking the chaperones groEL (involved in protein folding/refolding) or dnaK (involved in protein folding/refolding and disaggregation) would have a decreased viability when treated with paraquat as compared to the mutants not treated with paraquat. After doing three survival assay trials with paraquat, my results showed that my hypothesis is supported. Future research includes obtaining data for 10 full days, more trials, and testing other double mutants.

Jesus Salazar

Depression is a mood disorder suffered by many people. Research has shown a correlation between depression and an imbalance of the brain’s neurotransmitters. Depression isn’t completely understood, but it is believed that an imbalance in serotonin, a neurotransmitter, may be the contributing factor. ProzacTM is the most widely prescribed antidepressant, and it has helped over 54 million patients worldwide. It works by increasing the amount of serotonin present in the brain. Although ProzacTM doesn’t cure depression it does help to control its symptoms. Overall, the goal of this research was to synthesize Fluoextine (ProzacTM) in a stereoselective manner. To do this we started with 3-dimethylaminopropiophenone-HCl and reacted it with sodium borohydride to form an intermediate known as 3-dimethylamino-1-phenylpropanol. This product was then reacted with 4-chlorobenzotriflouride in the presence of dimethylacetamide and 1.0 M potassium t-butoxide to form the next intermediate, N,N-dimethyl-3-phenyl-3-(4-triflouromethylphenoxy)propanamine. This product was then reacted with phenyl chloroformate and hydrolyzed with water to form Fluoextine. 1H-NMR, IR, GC-MS, and thin-layer chromatography were used to analyze the products of each reaction. Future research would involve synthesizing Fluoextine in a stereoselective manner and determining if there is a difference in the activity between the two enantiomers of Fluoextine in preventing depression.

Crystal Brust

Research was performed on a Dionex Capillary Electrophoresis System I, which started in the Instrumental Analysis course in Winter 2008. The Capillary Electrophoresis System (CES) had unknown problems with it and the purpose was to discover what the problems were and to repair them. This part of the research continued past the Instrumental Analysis course and it was determined that there were issues with detection. Steps were taken to repair the detection issues and to interface a chart recorder with the instrument. When that segment was completed and the CES was fully operational trial runs were done to determine how well the CES would detect various amino acids. Solutions of 2.0mM L-phenylalanine and 2.0mM tryptophan were prepared and run on the CES with a buffer of 10mM sodium borate with 50mM boric acid. These trials showed successful detection of the two amino acids. Further research would include a trial run with 2.0mM L-tyrosine and trials using different buffers to determine which buffer would give the best detection results.

Memorial Day - No Seminar

No Seminar