What product of photosynthesis is used by all living organisms on Earth for respiration?

Photosynthesis is a very complex biochemical process. The essence of this process is the production of glucose, which serves as an energy source for plants and for most living organisms. It takes carbon dioxide and water to create glucose. During the synthesis, oxygen molecules remain. They are released into the atmosphere. It is used by all living organisms to carry out various life processes. Plants themselves use oxygen. They absorb it in the dark during the dark phase of photosynthesis.