* Carbon Dioxide (CO2): This is the primary source of carbon for building organic molecules. Plants obtain it from the atmosphere.

* Water (H2O): Water serves as the source of electrons and hydrogen ions (protons) for the process. Plants absorb water from the soil through their roots.

* Sunlight: This provides the energy needed to drive the chemical reactions of photosynthesis.

While not technically inorganic, chlorophyll is also essential for photosynthesis. Chlorophyll is a pigment found in chloroplasts that absorbs light energy.