  We compute the spectra and fluxes of the velocity and temperature fields in
Rayleigh-B\'{e}nard convection in turbulent regime for a wide range of Prandtl
numbers using pseudo-spectral simulations on $512^3$ grids. Our spectral and
flux results support the Kolmogorov-Obukhov (KO) scaling for zero Prandtl
number and low Prandtl number ($P=0.02$) convection. The KO scaling for the
velocity field in zero-Prandtl number and low-Prandtl number convection is
because of the weak buoyancy in the inertial range (buoyancy is active only at
the very low wavenumbers). We also observe that for intermediate Prandtl
numbers ($P=0.2$) the KO scaling fits better with the numerical results than
the Bolgiano-Obukhov (BO) scaling. For large Prandtl number ($P=6.8$), the
spectra and flux results are somewhat inconclusive on the validity of the KO or
BO scaling, yet the BO scaling is preferred over the KO scaling for these
cases. The numerical results for P=1 is rather inconclusive.
