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Role Of Glycine And Glyoxylate Decarboxylation In Photorespiratory Co2 Release, David J. Oliver
Role Of Glycine And Glyoxylate Decarboxylation In Photorespiratory Co2 Release, David J. Oliver
David J. Oliver
Mechanically isolated soybean leaf cells metabolized added glycolate by two mechanisms, the direct oxidation of glyoxylate and the decarboxylation of glycine. The rate of glyoxylate oxidation was dependent on the cellular glyoxylate concentration and was linear between 0.58 and 2.66 micromoles glyoxylate per milligram chlorophyll. The rate extrapolated to zero at a concentration of zero. The concentration and, therefore, the rate of oxidation of glyoxylate could be decreased by adding glutamate or serine to the cells. These substrates were amino donors for the transamination of glyoxylate to glycine. In the presence of these amino acids more CO2 was released from …
Formate Oxidation And Oxygen Reduction By Leaf Mitochondria, David J. Oliver
Formate Oxidation And Oxygen Reduction By Leaf Mitochondria, David J. Oliver
David J. Oliver
Mitochondria isolated from the leaves of several plant species were investigated for the presence of NAD-linked formate dehydrogenase. The NADH produced was oxidized by the electron transport sequence and was coupled to ATP synthesis. The amounts of formate dehydrogenase, and, thereby, the capacity for formate-dependent O2 uptake, varied greatly among species. While no activity was detectable in mitochondria from soybean leaves, the rate of formate oxidation by spinach mitochondria was about one-half the rate of malate oxidation. In spinach, only mitochondria from green tissues oxidized formate. These last two observations raise questions as to the role of this reaction and …