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Jorge Awapara

Bio: Jorge Awapara is an academic researcher from Rice University. The author has contributed to research in topics: Amino acid & Paper chromatography. The author has an hindex of 28, co-authored 61 publications receiving 2432 citations. Previous affiliations of Jorge Awapara include University of Texas Health Science Center at Houston & University of Texas at Austin.


Papers
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Journal ArticleDOI
TL;DR: The formation of succinate and alanine in equimolar amounts allows glycolysis to proceed anaerobically and the regeneration of NAD+ is made possible by two reductive steps in succinate formation.

142 citations

Journal ArticleDOI
TL;DR: Taurine was found in high concentration in all the marine organisms studied but was not found in several fresh-water and terrestrial organisms, indicating the possible role of taurine and other free amino acids in aquatic organisms.
Abstract: 1. Free amino acids of 17 species of aquatic invertebrates were determined by chromatographic methods.2. Qualitative differences in some amino acids were detected in organisms of different species. The concentration of alanine, arginine, aspartic acid, glutamic acid, glycine and taurine was measured and significant differences recorded.3. Taurine was found in high concentration in all the marine organisms studied but was not found in several fresh-water and terrestrial organisms.4. The possible role of taurine and other free amino acids in aquatic organisms is discussed.

139 citations

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TL;DR: The present work was conducted for the purpose of determining quantitatively by paper chromatography the transamination reaction in various organs of the rat and to determine the number of amino acids involved in the reaction.

130 citations

Journal ArticleDOI
TL;DR: According to the proposed pathway, glucose is degraded to phosphoenolpyruvate (PEP), but most of the PEP is readily carboxylated to oxalacetate by the action of a very active PEP-carboxykinase.

122 citations


Cited by
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Journal ArticleDOI

2,446 citations

Journal ArticleDOI
TL;DR: To determine if transaminase activity could be demonstrated in human serum and blood cellular elements and, if so, to study any variations in activity of this enzyme in the blood of normal and diseased man.
Abstract: Enzymatic transamination consists of the enzyme catalyzed reversible transfer of the alpha amino nitrogen of an amino acid to an alpha-keto acid with the synthesis of a second amino acid and a second alpha-keto acid. Enzymes catalyzing different transamination reactions are found widely distributed in animal tissues and have been shown to change in activity in some tissues during disease (1-3). These observations prompted the present study to determine if transaminase activity could be demonstrated in human serum and blood cellular elements and, if so, to study any variations in activity of this enzyme in the blood of normal and diseased man.

1,533 citations

Journal ArticleDOI
TL;DR: An updated overview of glutamine metabolism and its involvement in tumorigenesis in vitro and in vivo is provided, and the recent potential applications of basic science discoveries in the clinical setting are explored.
Abstract: The resurgence of research into cancer metabolism has recently broadened interests beyond glucose and the Warburg effect to other nutrients, including glutamine. Because oncogenic alterations of metabolism render cancer cells addicted to nutrients, pathways involved in glycolysis or glutaminolysis could be exploited for therapeutic purposes. In this Review, we provide an updated overview of glutamine metabolism and its involvement in tumorigenesis in vitro and in vivo, and explore the recent potential applications of basic science discoveries in the clinical setting.

1,285 citations

Journal ArticleDOI
TL;DR: The unique features of the early-appearing GABA signalling systems might help to explain how GABA acts as a developmental signal in the immature brain.
Abstract: In the mature brain, GABA (gamma-aminobutyric acid) functions primarily as an inhibitory neurotransmitter. But it can also act as a trophic factor during nervous system development to influence events such as proliferation, migration, differentiation, synapse maturation and cell death. GABA mediates these processes by the activation of traditional ionotropic and metabotropic receptors, and probably by both synaptic and non-synaptic mechanisms. However, the functional properties of GABA receptor signalling in the immature brain are significantly different from, and in some ways opposite to, those found in the adult brain. The unique features of the early-appearing GABA signalling systems might help to explain how GABA acts as a developmental signal.

1,095 citations

DOI
01 Jan 1974
TL;DR: Evidence for A m i n o Acids as T ransmi t t e r s as well as evidence for Synthesis and Storage are presented.
Abstract: 2. Evidence for A m i n o Acids as T ransmi t t e r s . . . . . . . . . . . . . . . . . . . . 99 2.1. Synthesis and Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 2.2. Synapt ic Release . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102 2.3. Postsynapt ic Act ion . . . . . . . . . . . . . . . . . . . . . . . . . . . 102 2.4. Postsynapt ic An tagon i s t s . . . . . . . . . . . . . . . . . . . . . . . . . 103 2.5. Inac t iva t ion and R e m o v a l . . . . . . . . . . . . . . . . . . . . . . . . . 104

1,090 citations