Energetic ice processing is thought to be the primary mechanism responsible for the interstellar synthesis of most saturated organic molecules that are considered to be precursors of prebiotic molecules. Because the gas and dust absorb most of the external UV radiation, the interiors of dark, dense molecular interstellar clouds reach temperatures as low as 10 K, ensuring the freezing of most molecules and the formation of ice mantles around dust grains. Interaction of these ices with cosmic-ray induced photons/electrons produces radicals whose diffusion at temperatures above 30 K results in radical-radical reactions that lead to the synthesis of complex organic molecules. In this presentation, I will explore the different underlying interstellar molecular formation mechanisms with specific emphasis on the fundamentals of photochemistry and radiation chemistry of cosmic ices. The recently installed laser-driven low-energy (< 7.4) photon source makes our laboratory the only one in the world with the capability to study the differences and similarities between condensed-phase reactions initiated by electrons and photons, each with energies below 10 eV, the approximate ionization threshold for a generic molecule. I will report on our recent studies of energetic processing of cosmic ice analogs of water, ammonia, and methanol, three molecular species which are found in relatively high abundance in interstellar ices.