They require energy from ATP hydrolysis to break down polymers into monomers. Catabolic and anabolic pathways are usually the reverse of one another TF. Metabolic Reaction An Overview Sciencedirect Topics In the example of sugar metabolism the first metabolic pathway synthesized sugar from smaller molecules and the other pathway broke sugar down. . During feedback inhibition metabolic pathway products serve as inhibitors usually allosteric of one or more of the enzymes usually the first committed enzyme of the pathway involved in the pathway that produces them. Catabolism is the breakdown of complex molecules into simpler ones. A series of enzyme-catalyzed steps most of which are operating near equilibrium but one or more is highly favorable and irreversible B. In the absence of enzymatic catalysis most biochemical reactions are so slow that they would not occur under the mild conditions of. Catabolic pathways release ener