Catabolism Definition

Catabolism is a set of enzyme-catalyzed reactions that breakdown large complex molecules into smaller units in living systems.

• The most important aspect of catabolism is the release of energy which is stores in the body in the form of ATP. 
• It is a destructive process consisting of different exergonic reactions that result in the release of energy.
• In addition to energy and units for anabolic reaction, catabolism also produces cellular wastes like urea, carbon dioxide, ammonia, lactic acid, etc.
• Catabolism is the breaking-down part of the metabolism which provides energy as well as resources for anabolism.
• The process of catabolism occurs in three distinct phases: In the first stage, large complex molecules are broken down into smaller particles where a small amount of energy is released in the form of heat.
• In the second stage, the smaller molecules are oxidized, releasing energy to form ATP. In the final stage, the molecules are oxidized to carbon dioxide via the Krebs cycle. 
• Catabolism might differ in different living systems based on the utilization of organic compounds as a source of carbon or electron donor. 
• Heterotrophs break down larger organic molecules in order to generate energy, whereas organotrophs generate energy by producing electrons from the breakdown of organic molecules.
• The most important catabolic process in living systems is cellular respiration where intermediate molecules from various other pathways meet to generate a large amount of energy.
• In growing cells, catabolism is often dominated by anabolism, but catabolism is essential for the release of energy required for the growth of the living system.
• Catabolism, like anabolism, is regulated by a set of enzymes that make sure to prevent excessive catabolic reactions.
• Catabolic reactions occur when the body is active and requires energy to perform different living activities.