Flexi Says: The flow of energy through living organisms in most ecosystems begins with photosynthesis. This process stores energy from sunlight in the chemical bonds of glucose. This energy transfers up the food chain as one organism eats another. For example, a grasshopper is a primary consumer that eats grass. Then a secondary consumer, a frog, eats the grasshopper. A frog is then eaten by a snake, a tertiary consumer which is then eaten by a hawk, the final consumer. By breaking the chemical bonds in glucose, cells release the stored energy and make the ATP (also known as adenosine triphosphate, an energy-carrying molecule) they need. The process in which glucose is broken down and ATP is made is called cellular respiration.
