The complete reaction is dependent on the CO 2 -carrying coenzyme biotin as well as ATP, but assume in your mechanism that the actual carboxylation step occurs with free CO 2 (you don’t need to accoun...The complete reaction is dependent on the CO 2 -carrying coenzyme biotin as well as ATP, but assume in your mechanism that the actual carboxylation step occurs with free CO 2 (you don’t need to account for the role played by biotin or ATP). P13.13:Suggest a likely mechanism for the following reaction in the biosynthesis of morphine, being sure to identify the structure of species X, which is released in the reaction.