  The hypercentral constituent quark model contains a spin independent
three-quark interaction inspired by lattice QCD calculations which reproduces
the average energy of SU(6) multiplets. The splittings are obtained with a
residual generalized SU(6)-breaking interaction including an isospin dependent
term. The long standing problem of the Roper is absent and all the 3- and
4-star states are well reproduced. The model has been used in a systematic way
for transverse and longitudinal electromagnetic transition form factor of the
3- and 4- star and also for the missing resonances. The prediction of the
electromagnetic helicity amplitudes agrees quite well with the data except for
low $Q^2$, showing that it can supply a realistic set of quark wave functions.
In particular we report the calculated helicity amplitude $A_{1/2}$ for the
$S11(1535)$, which is in agreement with the TJNAF data.
