This page explains that all living organisms rely on energy and matter, processed through metabolism, which includes catabolism (breaking down molecules) and anabolism (building larger molecules). Aut...This page explains that all living organisms rely on energy and matter, processed through metabolism, which includes catabolism (breaking down molecules) and anabolism (building larger molecules). Autotrophs, like plants, create organic molecules via photosynthesis, whereas heterotrophs, such as humans, obtain energy by consuming organic matter.