Plants make their own food by photosynthesis in chloroplasts. Light passes through the two membranes of the chloroplast and strikes these green disks, where light energy is converted to chemical energy. The sugar molecules produced by photosynthesis can be made into other molecules or broken down for energy. When sugars produced by photosynthesis are broken down, their energy is used to make ATP in mitochondria. ATP powers the work of the plant cell. Most organelles, like mitochondria, are found in both plant cells and animal cells. So, the next time you pass by a plant, remember that we have more in common than meets the eye.