title: The active chemical state of D-glyceraldehyde 3-phosphate in its reactions with D-glyceraldehyde 3-phosphate dehydrogenase, aldolase and triose phosphate isomerase.
abstract: Glyceraldehyde 3-phosphate exists as the geminal diol and the free aldehyde in the molar ratio 29:1 in aqueous solution. The rate constant of the conversion of diol into aldehyde is 8.7x10(-2)sec.(-1) in the pH range 7.3-8.6 at 20 degrees . The free aldehyde is the substrate for d-glyceraldehyde 3-phosphate dehydrogenase. Over a wide concentration range of enzyme the rate of conversion of diol into aldehyde is the rate-limiting process in the catalytic oxidation of d-glyceraldehyde 3-phosphate by NAD(+). Aldolase and triose phosphate isomerase both liberate d-glyceraldehyde 3-phosphate as the aldehyde. This suggests that the relatively slow diol-aldehyde interconversion does not restrict the rate of glycolysis.
mesh_terms: D055598:Chemical Phenomena; D002621:Chemistry; D005634:Fructose-Bisphosphate Aldolase; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases; D006019:Glycolysis; D006863:Hydrogen-Ion Concentration; D007535:Isomerases; D007700:Kinetics; D009243:NAD; D010756:Phosphoric Acids; D013057:Spectrum Analysis; D014306:Trioses
chemical_list: D010756:Phosphoric Acids; D014306:Trioses; D009243:NAD; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases; D005634:Fructose-Bisphosphate Aldolase; D007535:Isomerases