All organisms require chemical energy for growth, repair, physiological processes, regulation and reproduction.
Bioenergetics is the subject of a field of biochemistry that concerns energy flow through living systems.
This is an active area of biological research that includes the study of thousands of different cellular processes such as cellular respiration and the many other metabolic processes that can lead to production and utilization of energy in forms such as ATP molecules.
All organisms require chemical energy for growth, repair, physiological processes, regulation and reproduction. Organisms can be classified by how they obtain this energy. Autotrophs such as plants use light energy to build energy–rich organic molecules and then use those organic molecules for fuel. In contrast, heterotrophs such as animals must obtain their chemical energy from food, which contains organic molecules synthesized by other organisms. The flow of energy through an animal–its bioenergetics–ultimately limits the animal's behavior, growth, and reproduction and determines how much food it needs. Studying an animal's bioenergetics tells us a great deal about the animal's adaptations.