ASYMMETRIC DISTRIBUTION OF C ¹⁴ IN SUGARS FORMED DURING PHOTOSYNTHESIS

Dark and Photometabolism of Sugars by a Blue Green Alga: Tolypothrix tenuis

“…These studies were extracted from a dissertation submitted to the Graduate School, Cornell University, in partial fulfillment of the requirements for the degree of Doctor of Philosophy. 3 Present address: Department of Biology, Brandeis University, Waltham, Massachusetts, 02154. Anacystis nidulans and Chlorella pyrenoidosa ( 12) revealed a similar pattern of asymmetry, as described by Gibbs and Kandler (7).…”

“…The labeling patterni observed in the glucose synthesized (luring photosynthesis tenids toward symmlietry when compared to that synthesized in the dark. During photosynthesis the photosynthetic carbon cycle is active and it has been established that this cycle leads to complete randomization of isotope within the hexose molecule (7). The fact that both light and C02 were necessary to obtain the randomization of isotope wden 14CO2 or a sugar was substrate establishes the impbortant role of the photosynthetic carbon cvcle in explaining our results recorded in tables IV and V. Thus, when glvceraldehv(le-3-P is formed by the reactions of the oxidative pentose-P cycle.…”

Enhanced Dark CO2 Fixation by Preilluminated Chlorella pyrenoidosa and Anacystis nidulans

“…this conclusion is obtained from comparison of the distribution patterns of 14(C within the glycerate 3-P and glucose 6-P formed during enhanced dark '"CO2, fixation with that synthesized during a b)rief period of photosynthesis (tables II and 111). Photosynthetically synthesized glycerate 3-P and glucose 6-P showed the expected spreading of tracer into all carbon atoms (9,10). In sharp contrast, glycerate 3-P formed dutring the enhanced dark.…”

“…The product was found to be identical to the 2,4-dinitrophenyl-.hydrazine derivative of authenitic pyruvate. The components of each peak wvere: 1) Alaninle, with traces ox other neutral amino acids and some sugars, 2) Aspartic acid with a trace of glutamic acid, 3) Mostly malic acid, 4) Glucose 6-P with some fructose 6-P and pentose monophosphate, 5) Dihydroxyacetone-P with a small amount of pentose monophosphate, 6) Glycerate 3-P, 7) Unidentified, 8) Sedoheptulose-1,7-diP, 9) Fructose 1,6-diP, 10 …”

Asymmetric Distribution of C14 in the Glucose Phosphates Formed During Photosynthesis.

“…While Basshamn, Benson, Kay, Harris, Wilson and Calvin (1) have fotund a symmetrical distribution of C14 in frtuctose isolatecl from Scenedesmus following a brief photosynthesis in C1402, Gibbs and Kandler (2) have recently reported an asymmetric labeling pattern in the ollucose moiety of sucrose and starch both in Chlorella as well as the leaves of several higher plants. In experiments 1, 2 and 3, the Chloirella was incubated with the C'402 in the dalk for 5 min before an illumination of 4000 ft-c for 1 min was begun.…”