An organism consumes a molecule, S, as food. The amount of S available for the cell varies, but there is always at least a small amount of S available. S is the substrate for two non-allosteric enzymes, E1 and E2. E2 produces P2, a molecule that is absolutely required for the survival of the organism. E1 produces P1, a molecule that is beneficial for the cell to have, but is not absolutely required for its immediate survival. In no more than 5 sentences, explain how the organism ensures that it always makes P2 but only makes P1 when S is plentiful. (Draw illustrations and/or plots if you feel they’re helpful.)