JQuery :: Dynamic Call Property On Object ?

I got a javascript object with some propeties let's say

function Animal() {
this.id; this.name;
}

I need to call id function in a dynamic way to get and set its value: something like this

Animal animal = new Animal();
var propertyName = "id";
animal.+propertyName = "name";

I tried like this:

$animal = $(animal);
$animal[propertyName]();

but i receive animal.propertyName is not a function.Is there an elegant way to do it with jQuery?