  We calculate the chemical evolution of protoplanetary disks considering
radial viscous accretion, vertical turbulent mixing and vertical disk winds. We
study the effects on the disk chemical structure when different models for the
formation of molecular hydrogen on dust grains are adopted. Our gas-phase
chemistry is extracted from the UMIST Database for Astrochemistry (Rate06) to
which we have added detailed gas-grain interactions. We use our chemical model
results to generate synthetic near- and mid-infrared LTE line emission spectra
and compare these with recent Spitzer observations. Our results show that if H2
formation on warm grains is taken into consideration, the H2O and OH abundances
in the disk surface increase significantly. We find the radial accretion flow
strongly influences the molecular abundances, with those in the cold midplane
layers particularly affected. On the other hand, we show that diffusive
turbulent mixing affects the disk chemistry in the warm molecular layers,
influencing the line emission from the disk and subsequently improving
agreement with observations. We find that NH3, CH3OH, C2H2 and
sulphur-containing species are greatly enhanced by the inclusion of turbulent
mixing. We demonstrate that disk winds potentially affect the disk chemistry
and the resulting molecular line emission in a similar manner to that found
when mixing is included.
