  We present the results of the covariant spectator quark model applied to the
nucleon structure function $f(x)$ measured in unpolarized deep inelastic
scattering, and the structure functions $g_1(x)$ and $g_2(x)$ measured in deep
inelastic scattering using polarized beams and targets ($x$ is the Bjorken
scaling variable). The nucleon is modeled by a valence quark-diquark structure
with $S,P$ and $D$ components. The shape of the wave functions and the relative
strength of each component are fixed by making fits to the deep inelastic
scattering data for the structure functions $f(x)$ and $g_1(x)$. The model is
then used to make predictions on the function $g_2(x)$ for the proton and
neutron.
