Glutamate glutamine synthesis from

Examine the bioenergetics of the synthesis of glutamine synthesis from a-ketoglutarate via glutamate synthase or glutamate dehydrogenase (fig. 21.3). Is there a difference ... 

Adenosine-5-triphosphoric acid, magnesium sulfate, and cysteine bring about L-glutamine formation from ammonium L-glutamate. However, significant hexosamine synthesis is not observed when these three substances are incubated with ammonium L-glutamate in the presence of a residue-free supernatant from crushed, bacterial cells. L-Glutamine stimu-... 

Several hypotheses have been propounded to explain the continued formation of urea. One of the first was the suggestion that to the synthesis of urea there was a pathway alternative to the Krebs-Henseleit one (L7). Evidence for such a pathway had earlier been adduced by Bach (Bl), who concluded that, in the liver, glutamine formed from glutamic acid and ammonia could combine further with ammonia and... 

Fig. 42.14. Role of glutamine in the brain. Glutamine serves as a nitrogen transporter in the brain for the synthesis of many different neurotransmitters. Different neurons convert glutamine to y-aminobutyric acid (GABA) or to glutamate. Glutamine also transports excess NH4 from the brain into the blood. BCKA = branched-chain keto acids a-KG = a-ketoglutarate.

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