Examples of reactions and their attribution to different confidence levels. (a) Sucrose phosphate phosphohydrolase is identically described in both databases. (b) Ribulose bisphosphate carboxylase has a discrepancy in hydrogen content but protons involvement is ignored. (c) All substrates and product are validated in both databases, but the pyruvate kinase reaction with GTP/GDP as cofactors is only described in one database. (d) Acetyl adenylate and the acetyl-CoA synthetase reaction are only found in one database. (e) Both substrate and product are only found in one database. (f) Both sides of the reaction involve generic compound classes which are only used by one database.