The relationship between metabolism and energy is fundamental and intrinsic. Metabolism is the collection of chemical reactions in the body's cells that convert the food and beverages we consume into usable energy

. This energy is primarily stored and transferred in the form of adenosine triphosphate (ATP), which serves as the cellular currency for energy transactions

. Key points on their relationship:

• Metabolism involves two main processes:
  • Catabolism breaks down macronutrients (carbohydrates, fats, proteins) into simpler molecules like glucose, fatty acids, and amino acids, releasing energy in the process

* _Anabolism_ uses this energy to build and maintain body tissues, store energy, and support growth and repair

• Energy metabolism refers specifically to the biochemical pathways that extract energy from nutrients and convert it into ATP, which powers cellular activities such as muscle contraction, neuronal signaling, and biosynthesis

• Metabolic pathways like glycolysis, the citric acid cycle (Krebs cycle), and oxidative phosphorylation are central to energy production, tightly regulated by enzymes and cellular signals

• Energy balance is the relationship between calories consumed (food intake) and calories expended (physical activity and basal metabolic processes), which is regulated by metabolism

• Cellular energy sensors like AMPK monitor ATP levels and adjust metabolism to maintain energy homeostasis, promoting ATP production when energy is low and conserving energy when sufficient

In summary, metabolism is the body's system of chemical reactions that transform food into energy, primarily ATP, which fuels all physiological functions. Energy metabolism is the subset of these reactions focused on generating and managing this energy, making metabolism and energy fundamentally interconnected