What perform a process the opposite of photosynthesis to help plants use energy as food?

The process that performs the opposite of photosynthesis is cellular respiration. In this process, plants convert the glucose produced during photosynthesis into energy by breaking it down with oxygen. This energy is then used for growth, reproduction, and other vital functions. Essentially, while photosynthesis captures and stores energy, cellular respiration releases that energy for the plant's use.