Metabolis

Metabolis is a term encountered in some English-language texts as a variant spelling of metabolism, the collective set of chemical reactions that sustain life in organisms. In standard biochemistry, metabolism encompasses two broad classes of pathways: catabolic pathways that break down nutrients to harvest energy and reducing equivalents, and anabolic pathways that use energy to synthesize complex biomolecules and cellular structures.

ATP is the primary energy currency, while molecules such as NADH and FADH2 transfer electrons during respiration. Key metabolic pathways include glycolysis, the citric acid cycle, and oxidative phosphorylation in aerobic organisms, as well as photosynthesis in plants and algae. Lipid, amino acid, and nucleotide metabolism cover other essential substrates required for growth and maintenance.

Regulation of metabolism involves control of metabolic flux through enzyme activity, allosteric effectors, covalent modification, and hormonal signals. Pathway direction and rate are influenced by nutrient availability, energy status, and environmental conditions, as well as by cellular compartmentalization that separates processes.

Physiological and medical relevance is broad: metabolism is central to growth, maintenance, and reproduction. Disorders of metabolism include diabetes, thyroid imbalances, inborn errors of metabolism, and metabolic syndrome. Methods to study metabolism range from measuring metabolic rate and energy expenditure to metabolomics, which analyzes the concentration and interaction of metabolites in biological samples.

Terminology: in some sources metabolis may appear as a misspelling or shorthand variant; the conventional term is metabolism, with related adjectives such as metabolic.