Bibliography: leaves 151-166. This thesis describes the development of two novel and complementary analytical approaches for assaying cyanoalanine non-protein amino acids. These assays are used to determine the distribution of these compounds both within and between plants and to identify accessions of common vetch which contain low levels of the cyanoalanine non-protein amino acids in germplasm collections. These analytical tools are used to correlate toxicity observed in animal feeding experiments with the cyanoalanine content. This thesis covers also the first report of the use of diffuse reflectance using dispersive infrared spectrometry for the "in situ" quantification of specific organic components from plant tissue as well as the first use of micellar electrokinetic chromatography for the quantitative analysis of 9-fluorenylmethyl chloroformate (FMOC) derivatised and non-derivatised components of extracts from plant material.

Sudden changes in nutrient resources are common in the natural environment. Cells are able to adapt and propagate under changing environmental conditions by making adjustments in their cellular processes. These cellular adaptations involve genome-wide transcriptional reprogramming that results in the induction or repression of metabolic pathways. Specific enzymes are then synthesised and activated to maximise the use of the newly available nutrient sources. L-serine is one of the twenty proteinogenic amino acids, and can be synthesised in yeast by the glycolytic and gluconeogenic pathways when growing on fermentable or non-fermentable carbon sources or taken up from the environment when available. L-serine is metabolically linked to glycine and is a predominant donor of one-carbon units in one-carbon metabolism. L-serine is also a source of pyruvate and ammonia and contributes to other cellular processes including the biosynthesis of cysteine and phospholipids. Previous work has shown that yeast cells exhibit transcriptional induction of the one-carbon pathway and the genes involved in the synthesis of purine and methionine after the addition of 10 mM glycine. Here it is shown that addition of 10 mM L-serine did not, however, elicit the same transcriptional response. This is primarily due to differences in the uptake of glycine and L-serine in yeast. High concentrations of extracellular L-serine were required for yeast to show an increase in intracellular L-serine concentration of the magnitude required to trigger a noticeable cellular response. Despite L-serine and glycine being interconvertable via the SHMT isozymes and being a one-carbon donor, the genome-wide transcriptional response exhibited by cells in response to L-serine addition was markedly different to that seen for glycine. The predominant response to an increase in intracellular L-serine was the induction of the general amino acid control system and the CHA1 gene encoding the serine (threonine) dehydratase. Unlike glycine, addition of L-serine triggered only minor induction of the one-carbon pathway. A large portion of intracellular L-serine was converted to pyruvate and ammonia in the mitochondrion as the result of induction of CHA1. The high intracellular concentration of L-serine stimulated the cell to increase the production of oxaloacetate and to increase the biosynthesis of L-aspartate. Transient increases in the intracellular L-glutamate and L-glutamine were also observed after the addition of L-serine. The work presented in this study shows that large increase in the intracellular concentration of amino acid is required to trigger a significant transcriptional response. Yeast cells exhibit different transcriptional and metabolic responses to the addition of L-serine and glycine even though these two amino acids are closely metabolically linked. Addition of L-serine provokes the GAAC response, expression of the CHA1 gene and stimulates the biosynthesis of L-aspartate in yeast whereas addition of glycine induces the one-carbon pathway which leads to the biosynthesis of the purine nucleotides.

Includes bibliographical references (leaves 226-261). / xxiii, 261 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Investigates nitrogen utilization in some species of rumen bacteria with the object of understanding the role of ammonia versus exogenous amino acids in relation to microbial growth. / Thesis (Ph.D.)--University of Adelaide, Dept. of Animal Science, 1996?

Bibliography: leaves 151-166. / xi, 166 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / This thesis describes the development of two novel and complementary analytical approaches for assaying cyanoalanine non-protein amino acids. These assays are used to determine the distribution of these compounds both within and between plants and to identify accessions of common vetch which contain low levels of the cyanoalanine non-protein amino acids in germplasm collections. These analytical tools are used to correlate toxicity observed in animal feeding experiments with the cyanoalanine content. This thesis covers also the first report of the use of diffuse reflectance using dispersive infrared spectrometry for the "in situ" quantification of specific organic components from plant tissue as well as the first use of micellar electrokinetic chromatography for the quantitative analysis of 9-fluorenylmethyl chloroformate (FMOC) derivatised and non-derivatised components of extracts from plant material. / Thesis (Ph.D.)--University of Adelaide, Dept. of Plant Science, 1997

Thesis (Ph. D.)--University of Adelaide, Dept. of Plant Science, 1997. / Includes bibliographical references (leaves 151-166).

Thesis--Catholic Univ. of America. / Includes bibliographical references (p. 70-73).

Foi desenvolvido um conjunto de peças plásticas que permitem a montagem e representação dos aminoácidos mais comuns, bem como a construção de estruturas protéicas. Durante e após o desenvolvimento o material foi submetido a várias etapas de avaliação por professores (do ensino básico e universitário), alunos de pós-graduação e de graduação. A primeira etapa foi o desenvolvimento dos modelos em ambiente computacional, seguida da prototipagem das peças. Após discussão com a comunidade científica (apresentados na XXXVI Reunião Anual da SBBq em 2007) as sugestões foram implementadas nos modelos computacionais. Quatro moldes para injeção termoplástica foram projetados, detalhados e construídos, sob nossa orientação. As peças representando as estruturas que compõe os aminoácidos e ligações foram produzidas em grande escala e iniciou-se o processo final de avaliação. As peças apresentaram boas relações geométricas com as fórmulas estruturais dos aminoácidos obtidas de bancos de dados e livros didáticos. As conexões C&alpha;-amina e C&alpha;-carboxila permitem verificar a liberdade de rotação característica das cadeias polipeptídicas e as possibilidades dos ângulos de torção &Psi; e &Phi;, visualizando a restrição de rotação da ligação peptídica. Montando um conjunto de aminoácidos é possível construir uma cadeia polipeptídica e, através das ligações de hidrogênio, montar as estruturas secundárias principais (hélice-&alpha; e estruturas &beta;). Duas avaliações preliminares foram realizadas e a avaliação final ocorreu em uma oficina de atividades com 256 professores das áreas de ciências da natureza da rede publica do Estado de SP. Os resultados da avaliação foram extremamente positivos, sendo importante destacar a quantidade e o teor dos comentários elogiosos ao potencial de utilização do material, notadamente, dos professores de biologia e química. O material poderá inclusive auxiliar no preenchimento de lacunas conceituais que existem na formação dos professores e que foram observadas durante as atividades de avaliação. Este conjunto de peças, organizado na forma de um kit: Construindo Estruturas de Aminoácidos e Proteínas, foi submetido à avaliação do MEC e certificado por este órgão, passando a integrar o Guia de Tecnologias Educacionais 2008.<b/> / It was developed a set of plastic pieces that allow the assembly and representation of the most common amino acids, as well as the construction of protein structures. During and after development the material was submitted to several stages of evaluation by teachers (primary and university), graduate and undergraduate students. The first step was the development of models in the computing environment, followed by prototyping of parts. After discussion with the scientific community (presented at the XXXVI Annual Meeting of SBBq in 2007) suggestions were implemented in the computational models. Four thermoplastic injection molds were designed, detailed and constructed under our supervision. Parts representing the structures of amino acids and bonds were produced in large scale and it was started the final process of evaluation. The pieces had good geometric relationships with the structural formulas of amino acids obtained from databases and textbooks. The connections C&alpha;-amine and C&alpha;-arboxyl permit to check the freedom of rotation of the polypeptide chains and the possibility of torsion angles &Phi; and &Psi;, visualizing the restriction of rotation of the peptide bond. Assembling a set of amino acids is possible to build a polypeptide chain and, through hydrogen bonding, to assemble the main secondary structures (&alpha;-helix and &beta;-structures). Two preliminary evaluations were conducted and the final evaluation took place in a workshop with 256 teachers of the fields of natural sciences from public schools of the São Paulo State. The results of the evaluation were extremely positive and it is important to highlight the amount and content of approving comments for the potential of use of the material, especially from biology and chemistry teachers. The material may even assist in filling in conceptual gaps that exist in teacher instruction and that were observed during the evaluation activities. This set of pieces, arranged in the form of a kit: Building Structures of Amino Acids and Proteins, was submitted to MEC and certified by this organization, starting to integrate the Guide of Educational Technology 2008<b/>.

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No description available.

The problem with which this research was done was that of applying the IBM360 computer to the analysis of waveforms from a Beckman model 120C liquid chromatograph. Software to interpret these waveforms was written in the PLl language. For a control run, input to the computer consisted of a digital tape containing the raw results of the chromatograph run. Output consisted of several graphs and charts giving the results of the analysis. In addition, punched output was provided which gave the name of each amino acid, its elution time and color constant. These punched cards were then input to the computer as input to the experimental run, along with the raw data on the digital tape. From the known amounts of amino acids in the control run and the ratio of control to experimental peak area, the amino acids of the unknown were quantified. The resulting programs provided a complete and easy to use solution to the problem of chromatographic data analysis.