### Step 3: Refining the Model

Your reactions probably don’t all have a mass-action kinetic, so before you can run the actual simulation, you have to specify the correct kinetics for all the reactions. In order to do this, you navigate in the tree on the left to the reaction that you want to change. Or you can double click on the reaction in the reaction overview table. In the Reaction Settings window you can change all attributes of the reaction, especially the kinetics and the associated kinetic parameters.

If necessary, you can do the same for the species and the compartment. Just use the tree on the left to navigate to the model element you want to change and make the necessary changes in the dialog on the right.