. "Also acts on (3S,4R)-ketose 1-phosphates." . "The enzymes increase electron-attraction by the carbonyl group, some (Class I) forming a protonated imine with it, others (Class II), mainly of microbial origin, polarizing it with a metal ion, e.g. zinc." . . . "Fructose-bisphosphate aldolase" . "Aldolase" . "Fructose-1,6-bisphosphate triosephosphate-lyase" . "D-fructose-1,6-bisphosphate D-glyceraldehyde-3-phosphate-lyase" . . "D-fructose 1,6-bisphosphate = glycerone phosphate + D-glyceraldehyde 3-phosphate." . "Zinc" .