Question

what happens in metabolism reaction

Answer 1

These reactions occur in the steady state rather than all at once. ... Metabolic reactions can be catabolic (directed toward the breakdown of larger molecules to produce energy), or anabolic (directed toward the energy‐consuming synthesis of cellular components from smaller molecules).
Two types of metabolic reactions take place in the cell: 'building up' (anabolism) and 'breaking down' (catabolism). Catabolic reactions give out energy. They are exergonic. In a catabolic reaction large molecules are broken down into smaller ones.