This thesis investigates the ability of rainbow trout to modulate hepatic glucose production (Ra) and disposal (Rd). My goals were to determine: (1) if resting trout can modulate fluxes to cope with exogenous glucose; (2) how fluxes change during graded swimming; (3) how exogenous glucose affects swimming kinetics; and (4) if exogenous glucose affects cost of transport or performance. Results show that resting trout suppress Ra completely and stimulate Rd from 10.6 to 27.6 μmol kg-1 min-1. During swimming, fluxes increase from 15.6 to 21.9 μmol kg-1 min-1, but only at speeds >2.4 BL s-1. When given glucose, trout suppress Ra from 16.4 to 4.1 μmol kg-1 min-1 and stimulate Rd from 16.4 to 40.1 μmol kg-1 min-1. Glucose lowers metabolic rate but does not affect critical swimming speed. Therefore, this research shows that rainbow trout have a much better capacity for glucoregulation than generally suggested by current literature.

Soil microbiomes play pivotal roles to the health of the environment by maintaining metabolic cycles. One question is how will climate change affect soil bacteria over time and what could the repercussions be. To answer these questions, the Harvard Forest Long-Term Warming Experiment was established to mimic predicted climate change by warming plots of land 5℃ above ambient conditions. In 2017, 14 soil core samples were collected from Barre Woods warming experiment to mark 15 years since the establishment of the soil warming in that location. These samples underwent traditional metatranscriptomics to generate an mRNA library as well as a process coined cell-sorted or mini-metagenomics involving the sorting of single bacterial cells from the environment using FACS. This was followed by pooling into groups of 100 cells for more cost efficient genome recovery. 200 high-quality genomes were compiled, 12 of which were taxonomically identified as Acidobacteria. Acidobacteria are an extremely abundant and diverse phylum of bacteria that were found to be very well represented in the soil samples. Due to their abundance in many different soil environments as well as their known importance in many metabolic cycles, they were chosen as the candidate phylum to further investigate. Using a reference-based read mapping approach with the 12 Acidobacteria genomes and metatranscriptomic data, we identified over 3,000 differentially expressed genes within these organisms as a result of soil warming. Due to the diversity within the phylum itself, many of the genomes indicated different patterns of expression making it difficult to identify phylum-wide differential expression trends. However, the sigma70 factor, an important housekeeping gene used as a transcription regulator, was found to be up-regulated in a majority of the genomes. Over 30 different glycoside hydrolase encoding genes and glycosyltransferases were also found to be differentially expressed across the Acidobacteria reference genomes as well as 23 chemotaxis-related genes. Despite identifying four different groups of genes that showed statistically significant differences in expression levels, there may be more changes occurring in these soil bacteria and the soil microbiome as a whole due to climate change than previously measured by read-based analyses of metatranscriptomic data.

The genome of Escherichia coli harbors several catabolic operons involved in the utilization of a wide variety of natural compounds as carbon sources. The chitobiose (chu) operons of E.coli Is involved in the utilization of chitobiose(disaccharide of N-acety1-D-glucosamine) and cellbiose (disaccharide of glucose) derived from the two most abundant naturally occurring carbon sources on earth, chitin and cellulose respectively. The operon consists of the chbBCARFG genes coding for transport, regulation and hydrolysis functions required to utilize these compounds; the chuyBCA genes code for a multi-subuni PTS transporter ; the chuR codes for a dual function repressor/activator of the operon; the chbF codes for a phospho-glucosidase and the chbG codes for a protein of unknown function. The chu operon Is regulated by three transcription factors; NagC, a key regulator of the nag genes involved in amino sugar metabolism; ChbR, a dual function operon-specific regulator; and CRP_cAMP. The operon is repressed by NagC and ChbR in the absence of catabolic substrate. In the presence of chitobiose, expression is induced by the abrogation of NagC-mediated repression by GlcNAc-6-P generated by the hydrolysis of chitobiose-6-P and subsequent activation of transcription by ChbR and CPR-cAMP. Wild type E.coli connot utilize cellbiose due to the inability of cellbiose to induce expression from the operon. The simultaneous presence of a loss of function mutation in nagC and a gain –of-function mutation in chbR is necessary and sufficient to allow cellbiose to induce expression and confer on E.coli the ability to utilize cellbiose. The activation step by ChbR and CPR-cAMP requires an inducer that is recognized by ChbR. The chemical identity of the inducer and the mechanism of transcriptional activation by ChbR and CPR-cAMP are not understood. The studies described in the chapter 2 shows that chbG is essential for the utilization of the acetylated sugars chitobiose and chitotriose while it is dispensable for the sugars lacking the acety1group such as cellobiose and chitosan dimer, a disaccharide of N-glucosamine. ChbG is produced as a cytosolic protein and removes one acety1 group from chitobiose and chitotriose thus shows a mono-decetylase activity. Taken together, the observing suggest that ChbG deacetylates chitobiose-6-P and chitotriose-6-P producing the mono-decetylated from of the sugars. The deacetylateion is necessary for their recognition both as inducers by ChbR to activate transcription along with CRP-cAMP and as substractes by phosop-glucosidase ChbF. Cellobiose positive(Cel+) mutants carrying nagC delection and different gain-of-function mutations in chbR are independent of chbG for induction by chitobiose suggesting that the mutations in ChbR can allow it to recognize the acetylated form of chitobiose-6-P. Despite normal induction, the mutants to grow on chitobiose without chbG are consistant with the requirement of deacetylation for hydrolysis by ChbF. The prediction active site of chbG was validated by demonstrating the loss of chbG function upon alanine substitution of the putative metal binding residues. Vibro cholerace ChbG can complement the function of E.coli ChbG indicating that ChbG is conserved in both the organisms. The studies presented in chapter 3 address the mechanism of transcriptional activation of the chb operon by ChbR and CPR-cAMP. ChbR and CPR-cAMP function in a synergistic manner in response to the induction signal. The synergy is not because of their cooperative binding to the DNA. The role of CRP as a class I activator via the known mechanism involving interaction between the Activation region1 (AR1) and the C-terminal domain of the alpha subunit of RNA polymerase (CTD) was not crucial for the chb operon. A direct interaction between the two activators in virto was observed. Based on these results and the close spacing of the synergy is due to interaction between the two regulators bound to DNA that is enhanced in the presence of the inducer, binding about an optimal confirmation in ChbR required to interact with RNA polymerase. ChbR contacts different residues in the subunit in response to cellbiose and chitobiose; whereas it utilizes the known residues in the presence cellbiose, it appears to require different and unknown residues for induction in the presence of chitobiose. In conclusion, the studies reported in chapter 2 and 3 provide an understanding of the regulation of the chitin oligosaccharides utilization in E.coli at different levels. The broad implications of these studies and possible future directions are discussed in chapter 4. ChbG is an evolutionary conserved protein found in both prokaryotes and enkayotes including humans. ChbG homologs have been implicated in inflammatory bowel disorders in humans and development in metazoans. Therefore, the studies on chbG described in this thesis have been broader significance.

In multicellular organism, bioenergetic metabolism is strictly regulated toward efficient generation of ATP. However, in certain situations, such as in limiting oxygen or in the rapidly proliferating system like growing juvenile or cancer cells, organisms apply the metabolic strategy that favors the production of biomass (e.g., nucleotides, amino acids, and lipids) over efficiency of ATP generation. The conserved estrogen-related receptors (ERRs) are master regulators in controlling metabolic homeostasis, and good candidates for mediating the metabolic transition induced by hypoxia and development. First, we investigate how dERR influences hypoxic adaptation in Drosophila melanogaster. We find that dERR is required for a competent hypoxic response alone, or together with hypoxia inducible factor (HIF), which is the main transcription factor modulating the hypoxic adaptation. We show that dERR binds to dHIFα and participates in the HIF-dependent transcriptional program in hypoxia. In addition, dERR acts in the absence of dHIFα in hypoxia and a significant portion of HIF-independent transcriptional responses can be attributed to dERR actions, including up-regulation of glycolytic transcripts. These results indicate that competent hypoxic responses arise from complex interactions between HIF-dependent and -independent mechanisms, and that dERR plays a central role in both of these programs. Secondly, we examine how dERR modulates metabolic transition toward the fatty acid oxidation at late L3 larva stage. We show that dERR is essential for the expression of an uncharacterized long-chain-fatty-acid acyl-CoA synthetase, CG4500, which is subject to induction by starvation. Furthermore, late L3 larvae of dERR mutants exhibit altered lipid profiles with elevated medium-chain and long-chain fatty acids. Together, with the previous finding that ERR directs an early switch toward glycolysis in the embryo, our studies indicate that ERR is a master regulator of programmed metabolic shifts through Drosophila development.

Vernonia herbacea, Asteraceae, possui órgãos subterrâneos de reserva ramificados, os rizóforos, que acumulam frutanos do tipo inulina como carboidratos de reserva. Os frutanos são polímeros de frutose que são sintetizados pelas enzimas SST (sacarose: sacarose frutosiltransferase) e FFT (frutano:frutano frutosiltransferase) e despolimerizados pela FEH (frutano exohidrolase). Plantas desta espécie entram em dormência no final do outono, quando perdem os ramos aéreos e rebrotam na primavera seguinte; subseqüentemente ocorre a floração e o crescimento vegetativo no verão; ocorrem variações no teor e na composição dos frutanos durante o ciclo fenológico das plantas. O rizóforo apresenta crescimento geotrópico positivo, cujo ápice apresenta tecidos mais jovens em crescimento e a rebrota dos novos órgãos aéreos se dá pelo desenvolvimento das gemas situadas na região proximal do rizóforo, localizada próximo à superfície do solo. Considerando estas variações este trabalho visou à análise da distribuição espacial das atividades da SST, FFT, Invertase e FEH, bem do teor e composição dos frutanos nas regiões proximal, mediana e distal dos rizóforos de plantas de Vernonia herbacea, em diferentes fases de desenvolvimento e em plantas induzidas à brotação pela remoção dos órgãos aéreos. Também foram analisados esses parâmetros em plantas na fase vegetativa com os órgãos aéreos intactos ou excisados, mantidas em condições ambientais naturais ou em baixa temperatura. De maneira geral, as enzimas SST e FFT apresentaram atividades mais elevadas em plantas na fase vegetativa, enquanto a FEH apresentou atividade mais elevada em plantas na fase de brotação natural ou induzida e nos tratamentos sob baixa temperatura. Com relação à distribuição espacial das atividades enzimáticas, a SST e FFT apresentaram atividade mais elevada na região distal, que diminuiu no sentido proximal dos rizóforos. A FEH por sua vez apresentou atividade mais elevada na região proximal, diminuindo no sentido distal. Em geral, o conteúdo de fruto-oligossacarídeos foi mais elevado na região distal e diminuiu em direção à região proximal dos rizóforos. Os tratamentos com baixa temperatura levaram a uma maior proporção de frutooligossacarídeos, enquanto nas plantas induzidas à brotação, a proporção de fruto-polissacarídeos foi superior. Os menores valores de grau de polimerização médio (GP) das cadeias de frutanos foram detectados na região distal, sugerindo que as cadeias de frutanos nesses tecidos não apresentam o GP característico da espécie. Valores elevados de GP foram detectados na região proximal, e valores mais elevados ainda, em plantas na fase de brotação e sob baixa temperatura, coincidindo com atividades mais elevadas de FEH. Estes resultados sugerem que o mecanismo de ação da FEH em V. herbacea seja do tipo "single chain", pelo qual uma molécula da enzima se liga à cadeia de frutano degradando-a até a molécula de sacarose. Os experimentos realizados possibilitaram algumas deduções a respeito do mecanismo de ação das enzimas envolvidas no metabolismo de frutanos, e um maior conhecimento sobre a dinâmica de variação temporal e espacial destes carboidratos, em diferentes fases de desenvolvimento das plantas e em condições adversas ao desenvolvimento vegetal. / Vernonia herbacea, Asteraceae, bears branched underground reserve organs, rhizophores, that accumulate inulin-type fructans as reserve carbohydrates. Fructans are fructose polymers, that are synthesized by SST (sucrose: sucrose fructosyltransferase) and FFT (fructan:fructan frutosyltransferase) and mobilized by FEH (fructan exohydrolase). Plants of this species enter dormancy at the end of autumn, with senescence and abscission of the aerial organs and sprout in the following spring; flowering occurs subsequently followed by a period of vegetative growth in the summer. The concentration and composition of fructans vary during the phenological cycle of the plants. Considering this variation in fructans, and the positive geotropic growth of the rhizophores, with the apex presenting younger tissues (distal region) and the resprouting of the new aerial organs occurring in the opposite end of the organ (proximal region), close to the soil surface, the aim of this work was to analyze the spatial distribution of fructans and fructan metabolizing enzymes in the different regions of the rhizophores (distal, median and proximal) in plants of Vernonia herbacea in different developmental phases and plants induced to sprouting by the excision of the aerial organs. These parameters were also analyzed in intact plants in the vegetative phase and in excised plants, kept in natural environmental conditions or in low temperature. In general SST and FFT presented higher activities in plants in the vegetative phase, while FEH presented higher activity during sprouting, either under natural or induced sprouting and in plants under low temperature. Concerning the spatial distribution of the enzyme activities, SST and FFT presented higher activity in the distal region, decreasing towards the proximal region of the rhizophores. The FEH, on the other hand, presented higher activity in the proximal region, decreasing towards the distal region. In general, the content of fructo-oligosaccharides in the phenological phases studied was higher in the distal region and decreased towards the proximal region of the rhizophores. Low temperature led to a higher proportion of fructo-oligosaccharides, while in plants induced to sprouting the proportion of fructo-polysaccharides was higher. The lower values of average degree of polymerization (DP) of fructans chains were detected in the distal region. This indicates that fructan chain length in younger tissues is shorter then that characteristic of the species. Higher values of mean DP were detected in the proximal region and even higher DP was detected in this region in sprouting plants and in plants under low temperature, coinciding with the higher FEH activity detected in these conditions. These results suggest a mechanism of action for the FEH in V. herbacea of the "single chain" type, in which a molecule of the enzyme binds to the fructan chain degrading it completely before binding to the next fructan molecule. These studies allowed us to draw several conclusions regarding the mechanism of action of enzymes involved in the metabolism of fructans in Vernonia herbacea and regarding the dynamics of distribution of these carbohydrates and the related enzymes in different phases of development and in adverse conditions for plant development.

UDP-glucose pyrophosphorylase (UGPase) is an important enzyme of carbohydrate metabolism in all living organisms. The main aim of this thesis was to investigate the function and regulation of plant UGP genes as well as the UGPase proteins. Both in vivo and in vitro approaches were used, including the use of transgenic plants deficient in UGPase activity, and using purified proteins and their mutants to elucidate the structure/ function properties of UGPase. In both Arabidopsis and aspen, there are two highly similar UGP genes being actively transcribed, but not to the same extent. For both species, the UGP genes could be classified into two categories: a “house-keeping” gene and a subsidiary gene, with the former functioning universally in all the tissues to support the normal growth, whereas the latter usually expressed at a lower level in most of the organs/tissues tested. Besides, the two UGP genes were also found being differentially regulated under abiotic stress conditions, e.g. low temperature. By investigating the Arabidopsis T-DNA insertion mutants, which respectively have one or both of the UGP genes knocked out, we noticed that as little as 10% of the remaining UGPase activity could still support normal growth and development under controlled conditions, with little or no changes in carbohydrate contents, including soluble sugars (e.g. sucrose), starch and cell wall polysaccharides. Those plants, however, had a significantly decreased fitness under field conditions, i.e. the plants most deficient in UGPase activity produced up to 50% less seeds than in wt. Therefore, we concluded that UGPase is not a rate-limiting enzyme in carbohydrate synthesis pathways, but still is essential in viability of Arabidopsis plants. In order to characterize two Arabidopsis UGPase isozymes, both proteins were heterologously overexpressed in prokaryotic cells and purified by affinity chromatography. The two isozymes showed little differences in physical and biochemical properties, including substrate specificity, Km values with substrates in both directions of the reaction, molecular masses, isoelectric point (pI), and equilibrium constant. On the other hand, possibilities of distinct post-translational regulatory mechanisms were indicated, based on amino acid (aa) motif analyses, and on 3D analyses of derived crystal structures of the two proteins. We used the heterologous bacterial system also to overexpress barley UGPase and several of its mutants, both single mutants and those with whole domains/ exons deleted. As a result, we have identified several aa residues/ protein domains that may be essential for structural integrity and catalytic/ substrate-binding properties of the protein. For instance, we found that the last exon of UGPase (8 aa at the end of C-terminus) was important for the protein ability to oligomerize and that Lys-260 and the second-to-last exon were essential for pyrophosphate (but not UDP-glucose) binding. The data emphasized the critical role of central part of the active site (so called NB-loop) in catalysis, but also pointed out to the role of N-terminus in catalysis and oligomerization, but not substrate binding, and that of C-terminus in both catalysis/substrate binding and oligomerization.

Thesis (Ph. D.)--University of Washington, 2006. / Vita. Includes bibliographical references (leaves 137-143).

Thesis (MSc (Plant Biotechnology))--University of Stellenbosch, 2010. / Includes bibliography. / ENGLISH ABSTRACT: The study of plants on a sub-cellular level is an important, yet challenging area and its application allows for novel insight into the understanding of metabolism and its regulation. In this study I describe the development of a reverse phase liquid chromatography mass spectrometry (RPLC-MS) technique in which 29 phosphorylated and nucleotide sugars could be detected and quantified. The method was validated with the use of authentic standards and the system displayed very good linearity (Rª > 0.95), while the recovery of the standards added to the plant material before extraction was between 65 and 125%. Further, Arabidopsis thaliana wild type (Col-0) and adenylate kinase (adk1) mutant leaf discs were fed 13C labeled glucose over a period of 24 hours and harvested at defined time intervals. Non aqueous fractionation, and metabolite profiling via the above mentioned rpLC-MS method in conjunction with gas chromatography mass spectrometry (GC-MS) allowed for the detection and quantification of primary metabolites on a sub-cellular level as well as the determination of their relative isotopic label enrichments through primary carbon metabolism. Finally, a yeast complementation system was designed for the identification of tonoplast bound sucrose import proteins. The screening system identified 22 unique sequences from an Arabidopsis thaliana cDNA library. Four unknown sequences were identified, one of which displayed tonoplast membrane association upon in silico analysis. Three ATP-binding proteins were also identified as well as a sub-unit from the exocyst gene family. Further studies will include the functional characterization of the latter, as well as the development of additional cDNA libraries more suited for screening of sequences that encode sucrose importer proteins. / AFRIKAANSE OPSOMMING: Die studie van plante op a sub-sellulere vlak is ‘n belangrike maar uitdagende navorsingsarea en die toepassing daarvan dra by tot unieke insig tot ‘n beter begrip van metabolise regulasie. In die studie bespreek ek die ontwikkeling van ‘n teenoorgestelde fase vloeistof kromatografie massa spektrometrie (RPLC-MS) tegniek waarin 29 gefosforileerde en nukleotied suikers gevind en gekwantifiseer kon word. Geldigverklaring van die metode is bewerkstelling met die gebruik van oorspronklike standaarde and die systeem het baie goeie liniariteit (Rª > 0.95) getoon, terwyl die herstelbaarheid van standaarde wat bygevoeg is by die plant material voor ekstraksie tussen 65% en 125% was. Arabidopsis thaliana wilde type (Col-O) en die adenaliet kinase (adk1) mutant blaar dele is met 13C gemerkte glukose gevoed oor ‘n tydperk van 24 uur en geoes by spesifieke tydstippe. Nie-vloeibare fraksionering en metaboliet uitleg is vermag vanaf die genoemde RPLC-MS metode met behulp van gas kromotografie massa spektrometrie (GC-MS) wat die bepaling en kwantifikasie van primere metaboliete op n sub-sellulere vlak sowel as die bepaling van hul relatiewe isotropiese merker verrykers deur primere metabolisme toelaat. Verder is n gis komplementere systeem ontwerp vir die identifikasie van tonoplas gebinde sukrose invoer proteine. Die verkenningsysteem het 22 unieke volgordes opgelewer vanaf ‘n Arabidopsis thaliana kDNA biblioteek. Vier onbekende volgordes is geidentifiseer, een wat tonoplas membraan assosiasie toon met in silico analise. Drie ATP-bindings proteine is ook geidentifiseer asook ‘n sub-eenheid van die eksosyst geen familie. Verdere studies sal die funksionele karakterisering van die laaste protein insluit, asook die ontwikkeling van additionele kDNA biblioteke meer gepas vir verkenning sodiende identifiseer van volgordes wat sukrose invoer proteine vertaal.

Este trabalho descreve o planejamento, desenvolvimento e validação de um modelo de software educacional. O aplicativo é um ambiente multimídia de ensino e aprendizagem do Metabolismo dos Glicídios e o Ciclo de Krebs, denominado e-Metabolismo: Glicídios e contém um jogo de seqüência para o ensino de Bioquímica, denominado Diagrama Metabólico Dinâmico Virtual. O estudo de teorias pedagógicas e a experiência em aulas com os alunos do curso de medicina da Fundação Faculdade Federal de Ciências Médicas de Porto Alegre apontou a necessidade de mudanças no ensino de Bioquímica com uso das novas tecnologias de informação e comunicação. A justificativa do uso de um jogo virtual como método de ensino tem por base os resultados obtidos com o uso de um jogo de seqüência lógica em tabuleiro, na Disciplina de Bioquímica. O desenvolvimento do e-Metabolismo: Glicídios, tendo como referência a prática pedagógica baseada na epistemologia genética Jean Piaget, incluiu no seu planejamento a escolha de ferramenta de programação para permitir a interação do usuário (aluno) com o ambiente. O produto utiliza amplamente recursos de multimídia e pode ser disponibilizado num servidor ou em forma de CD-ROM. O ambiente virtual possibilita a interação do aluno com o ambiente e com colegas e professores através de ferramentas como, por exemplo, acesso a e-mails, chats, fóruns, mapas conceituais e diário de bordo. Instrumentos de avaliação de software foram estudados e aplicados com alunos de Disciplinas de Bioquímica no sentido de validar o software e-Metabolismo tanto no que se refere aos aspectos técnicos como a aprendizagem do conteúdo pelos alunos. Experiências com o uso do software foram, primeiramente, realizadas com alunos do curso de Medicina da FFFCMPA e depois com alunos de outros cursos. O primeiro grupo de alunos que avaliaram o e-Metabolismo foi formado pelos monitores da Disciplina. Mapas conceituais, testes escritos e avaliação dos registros deixados pelos usuários no próprio software foram utilizados como instrumentos de avaliação do conhecimento dos alunos. O grau de satisfação com o uso do método de estudo, foi avaliado por um questionário, cujas respostas foram analisadas e categorizadas. Os resultados obtidos indicam que o ambiente apresenta interface de fácil acesso, desperta o interesse, possibilita ao aluno escolher de que maneira quer fazer o seu estudo sem prejuízos no seu desempenho e facilita o estudo, sendo, portanto, considerado válido como instrumento educacional. Por se tratar de um ambiente dinâmico, deve ser constantemente atualizado, e a versão atual contém as modificações sugeridas por professores e alunos, facilitando o uso na Internet e o acompanhamento do aluno. / This work describes the planing, the development and the validation of a game-like educational software. This multimedia ambient was designed for the study of carbohydrates metabolic pathways and the Krebs's Cycle, called e-Metabolism: carbohydrates, and contains the sequential game, called Virtual Dynamic Metabolic Diagram. The study of pedagogical theories and experiments in classroom with medicine students of the “Fundação Faculdade Federal de Ciências Médicas de Porto Alegre”, pointed the necessity of changes in Biochemistry courses, involving new technologies of information and communication. The use of a game-like software as a tool for teaching is based on experiments related to the use of tray games at Biochemistry courses. The development of the e-Metabolism took as a reference the integrationists’ pedagogical practice, based on Jean Piaget's concepts, related to genetic epistemology and constructivism, yet allowing the professors to choose the teaching method they wish to use. This product integrates multimedia resources extensively, and can be used in computer networks or in the format of a CD-ROM. In the virtual environment students will be able to interact with the environment as well as with classmates and professors through such tools as chats, forums, concept maps and notepads. Software ’s evaluation Instruments were studied and applied with undergraduate students of Biochemistry classes in the way to value the eMetabolism software in its technical aspects and student’s content learning aspects. Conceptual maps, written tests and evaluation of user’s registers realized with this software where used as evaluation instruments of students knowledge. The level of satisfaction was evaluated by a questionnaire, which answers had been analyzed and categorized. The results show that the e-Metabolism is easy to use, awakes the interest and facilitates the study, improving the student performance and can be considered a valid educational instrument. Since this is a dynamic ambient and is constantly actualized, the current version contains the changes suggested by teachers and students, making easier to use it at the Internet and to do a better analysis of the student’s learning.

Este trabalho descreve o planejamento, desenvolvimento e validação de um modelo de software educacional. O aplicativo é um ambiente multimídia de ensino e aprendizagem do Metabolismo dos Glicídios e o Ciclo de Krebs, denominado e-Metabolismo: Glicídios e contém um jogo de seqüência para o ensino de Bioquímica, denominado Diagrama Metabólico Dinâmico Virtual. O estudo de teorias pedagógicas e a experiência em aulas com os alunos do curso de medicina da Fundação Faculdade Federal de Ciências Médicas de Porto Alegre apontou a necessidade de mudanças no ensino de Bioquímica com uso das novas tecnologias de informação e comunicação. A justificativa do uso de um jogo virtual como método de ensino tem por base os resultados obtidos com o uso de um jogo de seqüência lógica em tabuleiro, na Disciplina de Bioquímica. O desenvolvimento do e-Metabolismo: Glicídios, tendo como referência a prática pedagógica baseada na epistemologia genética Jean Piaget, incluiu no seu planejamento a escolha de ferramenta de programação para permitir a interação do usuário (aluno) com o ambiente. O produto utiliza amplamente recursos de multimídia e pode ser disponibilizado num servidor ou em forma de CD-ROM. O ambiente virtual possibilita a interação do aluno com o ambiente e com colegas e professores através de ferramentas como, por exemplo, acesso a e-mails, chats, fóruns, mapas conceituais e diário de bordo. Instrumentos de avaliação de software foram estudados e aplicados com alunos de Disciplinas de Bioquímica no sentido de validar o software e-Metabolismo tanto no que se refere aos aspectos técnicos como a aprendizagem do conteúdo pelos alunos. Experiências com o uso do software foram, primeiramente, realizadas com alunos do curso de Medicina da FFFCMPA e depois com alunos de outros cursos. O primeiro grupo de alunos que avaliaram o e-Metabolismo foi formado pelos monitores da Disciplina. Mapas conceituais, testes escritos e avaliação dos registros deixados pelos usuários no próprio software foram utilizados como instrumentos de avaliação do conhecimento dos alunos. O grau de satisfação com o uso do método de estudo, foi avaliado por um questionário, cujas respostas foram analisadas e categorizadas. Os resultados obtidos indicam que o ambiente apresenta interface de fácil acesso, desperta o interesse, possibilita ao aluno escolher de que maneira quer fazer o seu estudo sem prejuízos no seu desempenho e facilita o estudo, sendo, portanto, considerado válido como instrumento educacional. Por se tratar de um ambiente dinâmico, deve ser constantemente atualizado, e a versão atual contém as modificações sugeridas por professores e alunos, facilitando o uso na Internet e o acompanhamento do aluno. / This work describes the planing, the development and the validation of a game-like educational software. This multimedia ambient was designed for the study of carbohydrates metabolic pathways and the Krebs's Cycle, called e-Metabolism: carbohydrates, and contains the sequential game, called Virtual Dynamic Metabolic Diagram. The study of pedagogical theories and experiments in classroom with medicine students of the “Fundação Faculdade Federal de Ciências Médicas de Porto Alegre”, pointed the necessity of changes in Biochemistry courses, involving new technologies of information and communication. The use of a game-like software as a tool for teaching is based on experiments related to the use of tray games at Biochemistry courses. The development of the e-Metabolism took as a reference the integrationists’ pedagogical practice, based on Jean Piaget's concepts, related to genetic epistemology and constructivism, yet allowing the professors to choose the teaching method they wish to use. This product integrates multimedia resources extensively, and can be used in computer networks or in the format of a CD-ROM. In the virtual environment students will be able to interact with the environment as well as with classmates and professors through such tools as chats, forums, concept maps and notepads. Software ’s evaluation Instruments were studied and applied with undergraduate students of Biochemistry classes in the way to value the eMetabolism software in its technical aspects and student’s content learning aspects. Conceptual maps, written tests and evaluation of user’s registers realized with this software where used as evaluation instruments of students knowledge. The level of satisfaction was evaluated by a questionnaire, which answers had been analyzed and categorized. The results show that the e-Metabolism is easy to use, awakes the interest and facilitates the study, improving the student performance and can be considered a valid educational instrument. Since this is a dynamic ambient and is constantly actualized, the current version contains the changes suggested by teachers and students, making easier to use it at the Internet and to do a better analysis of the student’s learning.