Final answer:
Catabolic reactions involve the breakdown of larger molecules into smaller ones, releasing energy in the form of ATP. They are typically associated with oxidation reactions, not reduction, and 40 percent of the energy released is used to form ATP.
Step-by-step explanation:
Catabolic reactions are a type of metabolic process where large molecules such as carbohydrates, lipids, and proteins are broken down into smaller components, releasing energy. Contrary to being reduction reactions, catabolic reactions are often oxidation reactions because they involve the loss of electrons.
During catabolism, glucose breakdown is a common example, where glucose is converted into water and carbon dioxide through a series of oxidation steps during cellular respiration, releasing energy that is captured in the form of adenosine triphosphate (ATP).
About 40 percent of the energy released in catabolic reactions is used to form ATP, the energy currency of cells. This ATP powers vital cellular functions such as building new tissue or repairing damaged ones. It is important to note that catabolic reactions contribute to the creation of simpler compounds and are exergonic; they release more energy than they consume.