Synthesis and Interconversion of Glycine and Serine
1980; Elsevier BV; Linguagem: Inglês
10.1016/b978-0-12-675405-6.50015-2
Autores Tópico(s)Mass Spectrometry Techniques and Applications
ResumoPublisher Summary This chapter discusses the synthesis and interconversion of glycine and serine. Glycolate pathway is initiated by the production of glycolate in the chloroplasts. The glycolate is oxidized to glyoxylate from which glycine is formed by transamination. Glyoxylate is not necessarily produced only from glycolate. It is also formed as an intermediate of the glyoxylate cycle from threo-Ds-isocitrate by the action of isocitrate lyase. Serine is made in the mitochondria by reactions involving two molecules of glycine. One molecule is oxidatively decarboxylated and deaminated to produce an active hydroxymethyl group that becomes attached to the β-carbon of the second molecule. Most of the serine produced is converted, by way of hydroxypyruvic acid and glyceric acid, to sucrose and polysaccharides. In unicellular algae, more of the carbon in the glycolate pathway is destined for immediate synthesis of proteins, other nitrogen compounds, and organic acids. Serine is not necessarily made from glycine. In organisms other than plants, serine is made from phosphoglyceric acid.
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