Mica Piro Chapter 8: An Introduction to Metabolism An organism?s Metabolism Transforms Matter and Energy, Subject to the Laws of Thermodynamics (8.1) The totality of an organism?s chemical reactions is called metabolism It is an emergent property of life that arises from orderly interactions between molecules Organization of the Chemistry of Life into Metabolic Pathways A metabolic pathway begins with a specific molecule, which is then altered in a series of defined steps, resulting in a certain product Each step is catalyzed by a specific enzyme Metabolism as a whole manages the material and energy resources of the cell Some pathways release energy by breaking down complex molecules to simpler compounds?these degraditive processes are called catabolic pathways, or breakdown pathways