FIG. 8.

Fate of the ¹³C label of glycolaldehyde in the synthesis of d-erythrose 4-phosphate from d-erythrulose in two possible pathways. Abbreviations: ERU4P, d-erythrulose 4-phosphate; ERU1P, d-erythrulose 1-phosphate; DHAP, dihydroxyacetone 3-phosphate; GcerADP, d-glyceraldehyde 3-phosphate; G6P, glucose-6-phosphate. (A) Pathway leading to E4P via d-erythrulose 4-phosphate. (B) Pathway leading to E4P via d-erythrulose 4-phosphate, dihydroxyacetone 3-phosphate, d-glyceraldehyde 3-phosphate, and glucose-6-phosphate by the erythritol catabolic pathway and Embden-Meyerhof-Parnas and pentose phosphate pathways. Solid symbols indicate ¹³C-labeled carbon atoms.