In practical terms, plants do depend on and interact with other living creatures. You will notice that water appears on both sides of the equation. The light reaction occurs only during the daytime, and is driven by the energy of sunlight. In the light reaction, light received by the plant is used to create energy-holding chemicals, used in the later stages of photosynthesis for other metabolic process. This dark reaction takes place in many different steps, and the process actually varies in different types of plants.
Chloroplasts are present mostly in leaves, but are also present in green stems and unripe fruit.
As explained above, this adds up to a tremendous annual yield of energy and plant material.