ABSTRACT
Bioenergetics is the study of how cells transform energy. Cells use this energy for many different processes, including growth and development. When the energy required for biological processes is less than the available energy, excess energy is stored, often in adipose tissue, leading to obesity. However, not all fat tissues are for energy storage. Whereas white adipose tissue is the primary site for triglyceride storage, thermogenic adipose tissue consisting of brown and beige/brite adipocytes is specialized for energy expenditure. This chapter will discuss the fundamental processes that underlie the harvesting and usage of energy in the biosphere. We will cover the specific metabolic processes that generate energy and discuss the mechanisms by which organisms utilize the energy they harvest for work and thermogenesis, emphasizing the specific cellular bioenergetic mechanisms that exist in thermogenic adipocytes for converting chemical energy into heat. There are two basic strategies by which organisms waste energy for thermogenesis. The first is the dissipation of energy stored in chemiosmotic gradients across the inner mitochondrial membrane. The second means is by wasting ATP in reactions without harvesting work. An increased understanding of these processes may facilitate the development of strategies to combat obesity by altering bioenergetics.
