Robert G. Twarog

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Twarog, R. (University of Illinois, Urbana) and R. S. Wolfe. Role of butyryl phosphate in the energy metabolism of Clostridium tetanomorphum. J. Bacteriol. 86:112-117. 1963.-A partially purified butyrokinase from Clostridium tetanomorphum has been found to phosphorylate valerate, butyrate, isobutyrate, and propionate. The divalent cation requirement is(More)
Conservation of thiol ester bond energy through a reaction sequence involving phosphorolysis of acetyl coenzyme A by phosphotransacetylase (1, 2) and the subsequent formation of adenosine triphosphate from adenosine diphosphate and acetyl phosphate by acetokinase (3, 4) is well established in fermentative bacteria. A similar reaction sequence involving(More)
The anthranilate synthetase of Clostridium butyricum is composed of two nonidentical subunits of unequal size. An enzyme complex consisting of both subunits is required for glutamine utilization in the formation of anthranilic acid. Formation of anthranilate will proceed in the presence of partially pure subunit I provided ammonia is available in place of(More)
This study explored which of two modes of access to a biomedical database better supported problem solving in bacteriology. Boolean access, which allowed subjects to frame their queries as combinations of keywords, was compared to hypertext access, which allowed subjects to navigate from one database node to another. The accessible biomedical data were(More)
Enzymological studies were done to characterize the allosteric control of 3-deoxy-d-arabino-heptulosonate 7-phosphate (DAHP) synthetase in three species of Clostridium. Allosteric control was identified as feedback inhibition by phenylalanine and was qualitatively similar for the DAHP synthetases of C. butyricum, C. acetobutylicum, and C. tetanomorphum.(More)
OBJECTIVE To assess the degree to which information retrieved from a biomedical database can augment personal knowledge in addressing novel problems, and how the ability to retrieve information evolves over time. DESIGN This longitudinal study comprised three assessments of two cohorts of medical students. The first assessment occurred just before student(More)
This study examined the potential contribution that access to a database of biomedical information may offer in support of problem-solving exercises when personal knowledge is inadequate. Thirty-six medical students were assessed over four occasions and three domains in the basic sciences: bacteriology, pharmacology, and toxicology. Each assessment(More)
All enzymes of the tryptophan synthetic pathway were detectable in extracts from wild-type Acinetobacter calco-aceticus. The levels of these enzymes were determined in extracts from a number of auxotrophs grown under limiting tryptophan. In each case only anthranilate synthetase was found to be present in increased amounts, whereas the specific activities(More)