Metabolic

Metabolic refers to metabolism, the total set of chemical reactions in living organisms that sustain life. Metabolism enables cells to extract energy from nutrients and to synthesize macromolecules. It involves catabolic pathways that break down molecules to release energy and anabolic pathways that build cellular components from smaller precursors. Metabolic processes are organized into interconnected pathways and occur within specific compartments.

Energy currency such as ATP, and redox carriers like NADH and FADH2, are central to metabolic reactions, which are catalyzed by enzymes. Regulation occurs through hormones, allosteric control, and the cellular energy status, allowing metabolic flux to adapt to nutrient availability and physiological conditions. Basal metabolic rate describes the energy expenditure of an organism at rest, while other measures reflect activity level and health. Core metabolic pathways include glycolysis, the citric acid cycle, and oxidative phosphorylation, which together harvest energy from carbohydrates, fats, and proteins. Metabolic processes also encompass biosynthetic routes that generate nucleotides, amino acids, lipids, and other essential molecules; photosynthesis in plants and algae is a related form of metabolism that converts light energy into chemical energy.

Disruptions in metabolism underlie many diseases, such as diabetes, obesity, and various inborn errors of metabolism, as well as metabolic syndrome. Metabolic engineering seeks to optimize pathways for the production of fuels, polymers, pharmaceuticals, and other useful compounds. Metabolic research informs nutrition, pharmacology, and systems biology, contributing to understanding health, disease, and the adaptability of living systems.