BackboneJS with your base model

base.js

(function(Sternenbund, $, undefined) {
    Sternenbund.Model = Backbone.Model.extend({
        url: function() {
            return this.urlRoot+'/'+this.id+'.json';
        }
    });

    // ..

    Sternenbund.Venad = Sternenbund.Model.extend({
        id: null,
        name: null,
        researches: new Sternenbund.ResearchCollection(),
        urlRoot: '/api/venad'
    });

    // .. 

}(window.Sternenbund = window.Sternenbund || {}, jQuery));