The process by which animals convert food into energy is called metabolism. Metabolism encompasses a series of biochemical reactions occurring within the cells that break down food molecules to generate energy, which is essential for maintaining vital functions such as growth, reproduction, and maintaining homeostasis. These reactions involve two primary types: catabolism, which breaks down larger molecules to release energy, and anabolism, which builds up smaller molecules to create cellular components. Metabolism varies among species based on their diet and environment, influencing their survival and adaptation strategies.