All organisms use the energy in chemical bonds to carryout the processes of life. In organisms, this oxidation is performed on chemical bonds in a controlled manner called metabolism. Because reduction and oxidation must be performed efficiently, organisms have developed mechanisms to accomplish these tasks in a controlled manner. Organisms must also contain all their functions to maximize efficiency. These things require that organisms have structure and functions that are different from normal physical processes.
Organisms use many elements to build their structures and functions.
Ultimately, all energy on the earth comes from the sun. Sunlight is simply a form of radiation, and organisms must trap the energy if they are to use it. Only plants have the ability to trap solar energy and convert it into a form that is useful for life. Once it is in the form of chemical bonds, then plants and animals can use the energy to grow, reproduce and maintain themselves. When an organism has an excess of energy, some of it can be stored.