  We study the dynamics of a polymer, described as a variant of a Rouse chain,
driven by an active terminal monomer (head). The local active force induces a
transition from a globule-like to an elongated state, as revealed by the study
of the end-to-end distance, whose variance is analytically predicted under
suitable approximations. The change in the relaxation times of the Rouse-modes
produced by the local self-propulsion is consistent with the transition from
globule to elongated conformations. Moreover also the bond-bond spatial
correlation for the chain head results to be affected and a gradient of
over-stretched bonds along the chain is observed. We compare our numerical
results both with the phenomenological stiff-polymer theory and several
analytical predictions in the Rouse-chain approximation.
