Structure and function relationships in hemeproteins, like the unique hemoglobin I from Lucina pectinata. For example, using "site directed mutagenesis" we tailor the structure of this hemoglobin. Its chemical structure is then studied by Fourier Transform infrared, resonance Raman vibrational analysis, and NMR spectroscopies. This is followed by the kinetic study of the reaction between hemoglobin and ligands (for example, O2, CO, NO, and H2S) using time - resolved (pump and probe) infrared and resonance Raman techniques. Ultrafast geminate chemical dynamics are studied also in our laboratory using time - resolved (pump and probe) picosecond and femtosecond spectroscopy.