The glucose required for cellular respiration is produced by plants. Plants go through a process known as photosynthesis. ... This energy is then converted along with water and carbon dioxide from the atmosphere into glucose and oxygen. Photosynthesis. ... During photosynthesis, plants absorb sunlight and carbon dioxide from the air. Through a series of steps, much like cellular respiration, they convert these reactants into the products oxygen and glucose. The plants then can use the oxygen and glucose to make ATP in cellular respiration