Examples of thermodynamically infeasible cycles and their resolution. Dashed lines indicate the direction of flux through the cycle forming reactions. A) A cycle containing three reactions. B) The fixed cycle from 1A after the removal of a single reaction with minimal literature evidence. C) A cycle containing seven reactions. D) The original cycle correction for 1C, involving the removal of a reaction with minimal literature evidence. E) The final cycle correction upon examination of 13C-MFA data .