  The accretion flow around the Galactic Center black hole Sagittarius A* (Sgr
A*) is expected to have an electron temperature that is distinct from the ion
temperature, due to weak Coulomb coupling in the low-density plasma. We present
four two-temperature general relativistic radiative magnetohydrodynamic
(GRRMHD) simulations of Sgr A* performed with the code KORAL. These simulations
use different electron heating prescriptions, motivated by different models of
the underlying plasma microphysics. We compare the Landau-damped turbulent
cascade model used in previous work with a new prescription we introduce based
on the results of particle-in-cell simulations of magnetic reconnection. With
the turbulent heating model, electrons are preferentially heated in the polar
outflow, whereas with the reconnection model electrons are heated by nearly the
same fraction everywhere in the accretion flow. The spectra of the two models
are similar around the submillimetre synchrotron peak, but the models heated by
magnetic reconnection produce variability more consistent with the level
observed from Sgr A*. All models produce 230~GHz images with distinct black
hole shadows which are consistent with the image size measured by the Event
Horizon Telescope, but only the turbulent heating produces an anisotropic
`disc-jet' structure where the image is dominated by a polar outflow or jet at
frequencies below the synchrotron peak. None of our models can reproduce the
observed radio spectral slope, the large near-infrared and X-ray flares, or the
near-infrared spectral index, all of which suggest non-thermal electrons are
needed to fully explain the emission from Sgr A*.
