This review describes recent progress of atomistic simulations to promote the understanding of the role of the solvent in biophysics and biochemistry. Fundamental aspects of aqueous solutions and their importance for the rationalization of biomolecular arrangements and metabolic transport are discussed. Many of these insights were obtained from molecular dynamics simulations performed during the last three decades. In combination with quantum mechanical descriptions this approach nowadays advanced to a reliable tool for the investigation of biochemical reactions. Apart from passive coordination of the reactants, the solvent studies may also address proton transfer over chains of hydrogen bonded molecules.