Metabolism

In a broad sense, it corresponds to metabolism, while in a narrow sense – to intermediary metabolism, encompassing the entirety of enzymatic reactions occurring within cells, ensuring the breakdown of complex compounds, as well as their synthesis and interconversions. The intermediate products formed are called metabolites. For example, the breakdown product of carbohydrates (pyruvate) after oxidation converts to acetyl-CoA, which is used in the synthesis of fatty acids, certain amino acids – in gluconeogenesis. Reactions synthesizing complex compounds from simple ones are called anabolic, and their totality – anabolism. These reactions require energy for their occurrence, hence they are called endergonic. The sum of enzymatic breakdown reactions of complex compounds into simpler ones forms catabolism. During such reactions (known as exergonic), the reserves of free energy in the system decrease. Both sides of metabolism – anabolism and catabolism are interconnected over time and space. Individual metabolic pathways in various classes of organisms are similar.

Source | Glossary of Most Commonly Used Biomedical Terms and Concepts | Lithuanian University of Health Sciences | Academician Professor Antanas Praškevičius, Professor Laima Ivanovienė