What four substances are recycled during photosynthesis and respiration?

Four substances which are recycled during photosynthesis and respiration are glucose, water, carbon dioxide, and oxygen.
 Energy in the photosynthesis cannot be recycled and should be constantly available. The products of photosynthesis are the reactants of the respiration and vice versa.
 Photosynthesis involves the use of energy from the sun, carbon dioxide, and water to produce oxygen and glucose. On the other hand, respiration uses oxygen and glucose to produce water and carbon dioxide.
 Human beings, plants, and animals depending on the cycle of photosynthesis and respiration for survival. Oxygen which is produced by plants during the process of photosynthesis is what animals and humans inhale for the blood to be transported to cells for respiration from the body then it is absorbed by plants to help provide the energy they need for development and growth.

We can plant more trees and plants.