  There is evidence for existence of massless Dirac quasi-particles in
graphene, which satisfy Dirac equation in (1+2) dimensions near the so called
Dirac points which lie at the corners at the graphene's brilluoin zone. We
revisit the derivation of Dirac equation in (1+2) dimensions obeyed by
quasiparticles in graphene near the Dirac points. It is shown that parity
operator in (1+2) dimensions play an interesting role and can be used for
defining "conserved" currents resulting from the underlying Lagrangian for
Dirac quasi-particles in graphene which is shown to have U_{A}(1)*U_{B}(1)
symmetry. Further the quantum field theory (QFT) of Coulomb interaction of 2D
graphene is developed and applied to vacuum polarization and electron self
energy and the renormalization of the effective coupling g of this interaction
and Fermi velocity $v_{f}$ which has important implications in the
renormalization group analysis of g and v_{f}.
