Motivated by the recent experiment on bosonic mixtures of atoms and molecules, we investigate pairing superfluid-insulator (SI) transition for bosonic mixtures of atoms and molecules in a one-dimensional optical lattice, which is described by an extended Bose-Hubbard model with atom-molecule conservation (AMC). It is found that AMC can induce an extra pair-superfluid phase though the system does not demonstrate pair-hopping. In particular, the system may undergo several pairing SI or insulator-superfluid transitions as the detuning from the Feshbach resonance is varied from negative to positiv...
