  Using Langevin Dynamics simulations, we study a simple model of
interacting-polymer under a periodic force. The force-extension curve strongly
depends on the magnitude of the amplitude $(F)$ and the frequency ($\nu$) of
the applied force. In low frequency limit, the system retraces the
thermodynamic path. At higher frequencies, response time is greater than the
external time scale for change of force, which restrict the biomolecule to
explore a smaller region of phase space that results in hysteresis of different
shapes and sizes. We show the existence of dynamical transition, where area of
hysteresis loop approaches to a large value from nearly zero area with
decreasing frequency. The area of hysteresis loop is found to scale as
$F^{\alpha} \nu^{\beta}$ for the fixed length. These exponents are found to be
the same as of the mean field values for a time dependent hysteretic response
to periodic force in case of the isotropic spin.
