Along with plants and algae, in which organisms can photosynthesis occur?

Both photosynthetic organisms.

The one component in photosynthesis that can't be recycled but must be constantly available is energy.

Light energy, mostly from sunlight, is the main requirement for photosynthesis to occur.

Photosynthesis is a process wherein light energy is converted into chemical energy.

Chemical energy is generated to support the various activities of a plant or an organism.