March 22, 2013
Kegan Sunderlan ‘13Hamline UniversityBiology Senior SeminarAbstract:Raman Spectroscopy of Spontaneously Absorbed Monolayers Raman Spectroscopy signals provided depolarization ratios for CCl4. These signals confirm that our data collection system is working. A spectra for a thin film of hexacontane was also obtained for use as a reference. Therefore, the system can now be applied to gain insight into the organization of spontaneously absorbed monolayers of hydrophobic hydrocarbon chains on surfaces.
Alyssa Renn ‘13Hamline University
Biology Senior Seminar
Abstract:
Bioinformatic and Functional Analysis of ACC-Deaminase Homologues in Strains of Sinorhizobium
Agriculture is dependent on biologically fixed nitrogen occurring between rhizobacteria and plants. Elevated levels of ethylene inhibit the association between plants and rhizobacteria preventing nitrogen fixation. The enzyme 1-aminocyclopropane-1-carboxylate deaminase (ACCD) decreases the level of ethylene in plants by converting 1-aminocyclopropane-1-carboxylate (ACC), a precursor to ethylene, to α-ketobutyrate and ammonia. This study investigated ACCDs among 48 Sinorhizobium strains. Genomic analysis revealed proteins with a range of 33 to 100% identity to previously reported ACCDs. The ACCD homologs were analyzed using biochemical assays, sequence alignments and comparative 3D modeling of pyridoxal-5’-phosphate (PLP) active sites. Biochemical assays showed that only proteins with highly conserved amino acid sequences (>90%) catalyzed the conversion of ACC to α-ketobutyrate and ammonium. Sequence alignments and comparative 3D modeling of the PLP active sites suggest that enzymatic inactivity is due to the absence of a hydrogen bonding from a glycine residue to the nitrogen atom of PLP cofactor.
Charles Schweitzer ‘13Hamline University
Biology Senior Seminar
Abstract:
The Effects of Rice Bran on the Inhibition of Carcinogenesis
This study was undertaken to determine the efficacy of rice bran diets in treating mouse models of breast, prostate, and intestinal cancer. The mouse models were put into testing groups and provided with the standard diet, or a diet supplemented with either 10% or 30% bran. The results showed that there was no significant changes in the occurrence of carcinogenesis in either the prostate or the breast cancer models. The intestinal cancer model had a 51% decrease in occurrences of cancer when fed a 30% bran diet, while the 10% bran diet group had no significant difference from the control group.