The resonance Raman intensities for parsley plastocyanin, a blue copper protein involved in electron transport in plant photosynthesis, have been measured at wavelengths throughout the S(Cys) --> Cu charge-transfer absorption band centered at 597 nm in an effort to determine the structural and dynamic role of inner- and outer-sphere reorganization in the kinetics of charge transfer. Self-consistent analysis of the absorption band and the resulting resonance Raman excitation profiles demonstrates that the charge-transfer absorption band is primarily homogeneously broadened. The homogeneous line width is composed of population decay and solvent-induced dephasing. The excited-state lifetime of 20 +/- 15 fs calculated here from the observed fluorescence suggests that the charge-transfer state decays rapidly via lower-lying ligand-field states. The spectral line shape dictates that this population decay be modeled as a Gaussian of line width 230 cm(-1). The reorganization energy obtained from the resonance Raman intensities of specific vibrations is 0.19 eV. if the reorganization energy of the protein as measured from the solvent-induced dephasing component of the homogeneous line width is included, the observed reorganization energy is 0.25 eV, in quantitative agreement with a previous upper limit of 0.3 eV measured for the reorganization energy upon electron transport at the copper site in azurin, a similar blue copper protein. A crude comparison of the reorganization energies upon electron transport and charge transfer suggests that charge transfer may be a somewhat useful model for the geometry changes upon electron transfer. The resonance Raman spectrum indicates that reorganization occurs primarily along normal modes that involve the Cu-S(Cys) stretch, but significant reorganization also occurs along specific normal modes that involve internal cysteine stretches, Cu-N(His) stretches, and protein internal motions. An important result of this work is the two mechanisms by which the protein environment contributes to the reorganization energy : through coupling into specific resonance-enhanced normal modes and through a solvent-induced dephasing contribution as evidenced by the homogeneous line width. These results are compared to those of other methods for determining reorganization energies and are discussed in terms of the role of the environment in controlling electron- and charge-transfer processes.