Here's how it works:

* Photosynthesis: Plants and some bacteria use sunlight to convert carbon dioxide and water into glucose (a type of sugar) and oxygen. This process is called photosynthesis. Glucose is the primary energy source for plants.

* Food Chain: Animals eat plants or other animals that have eaten plants. This way, the energy from the sun is transferred through the food chain.

* Cellular Respiration: All living things use a process called cellular respiration to break down glucose and release the stored energy in its chemical bonds. This energy is then used to power all the life processes, such as growth, movement, and reproduction.

So, while we might get our energy from the food we eat, the ultimate source of that energy is the sun.