intramolecular oxidoreductase activity, interconverting aldoses and ketoses ribose isomerase activity https://github.com/geneontology/go-ontology/issues/30193 MetaCyc:RIBOSE-ISOMERASE-RXN Catalysis of the reaction: aldehydo-D-ribose = D-ribulose. EC:5.3.1.20 D-ribose aldose-ketose-isomerase activity RHEA:20796 molecular_function GO:0050261 KEGG_REACTION:R01081 D-ribose ketol-isomerase activity D-ribose isomerase activity