The liver plays a critical role in metabolism by regulating various physiological processes. It is responsible for the synthesis of proteins, storage of nutrients like vitamins and minerals, and detoxification of harmful substances. Additionally, the liver converts excess glucose into glycogen for storage and can release it when needed, ensuring a stable energy supply. Through these functions, the liver helps maintain metabolic homeostasis, influencing how the body utilizes different macronutrients and regulates overall energy levels in response to dietary intake and physical activity.