Computer simulations are run with the model using the following initial conditions (starting numbers of molecules). bcat: 100,000 cyto, 0 nuc importin: 20,000 all other species: 0 dc: 10,000 nucpore: 5,000 proteasome: 5,000 rangtpnuc: 25,000 to simulate what happens when wnt binds to frizzled, you run simulations where you inactivate dc by removing reaction (1) from the model. when you do this, nuclear bcat begins to accumulate, but then reaches a maximum when only 20,000 bcat molecules have been imported. this does not match well with your experimental measurements, which indicate that 90% of bcat is imported to the nucleus when wnt ligand is added to cells. what might be causing the incorrect result in your model? suggest a modification to the model (which can include additional reactions) that could correct this problem. if you do include additional reactions, show how they would modify the equations from (a).