MAM20019r has no synthesis routes

[liamkelley93]

The ER-localized version of FMNH2, MAM20019r, participates in 5 reactions:

• MAR20021
• MAR20023
• MAR20025
• MAR20027
• MAR20029

In each case, FMNH2 acts as a reactant in a non-reversible reaction. As a result, there is no synthesis route for the metabolites, and all of these reactions must have a flux of 0 under steady-state. I don't know whether this should be addressed by the reactions having reversibility, or whether FMNH2 transport into the ER is missing, or what.