for ribosome_kb in cell.observables.get_one(id='ribosome_obs').expression.species:
                ribosome_species_type_model = model.species_types.get_one(id=ribosome_kb.species_type.id)
                ribosome_model = ribosome_species_type_model.species.get_one(compartment=cytosol)

                reaction.participants.add(ribosome_model.species_coefficients.get_or_create(coefficient=-1))