Definition: An interaction in which molecules of one or more PhysicalEntity pools are physically transformed and become a member of one or more other PhysicalEntity pools. Rationale: Conversion is Comments: Conversions in BioPAX are stoichiometric and closed world, i.e. it is assumed that all of the participants are listed. Both properties are due to the law of mass conservation. Usage: Subclasses of conversion represent different types of transformation reflected by the properties of different physicalEntity. BiochemicalReactions will change the ModificationFeatures on a PhysicalEntity, Transport will change the Cellular Location and ComplexAssembly will change BindingFeatures. Generic Conversion class should only be used when the modification does not fit into a any of these classes. Example: Opening of a voltage gated channel.