  The momentum distributions of the constituent quarks inside the nucleon and
the prominent electroproduced nucleon resonances are investigated in the two
most sophisticated, available quark potential models, based respectively on the
assumption of the valence + gluon dominance and on the exchange of the
pseudoscalar Goldstone-bosons arising from the spontaneous breaking of chiral
symmetry. It is shown that both models predict a large, similar content of
high-momentum components, due to the short-range part of the interquark
interaction, which affect the behaviour of both elastic and transition
electromagnetic form factors at large values of the momentum transfer. The
electromagnetic form factors are calculated within a relativistic approach
formulated on the light-front, adopting a one-body current with constituent
quark form factors. The results suggest that soft, non-perturbative effects can
play a relevant role for explaining the existing data on elastic as well as
transition form factors (at least) for Q**2 ~ 10 - 20 (GeV/c)**2.
