Introduction to metabolism

Introduction to metabolism Definition of catabolic and anabolic pathways INTRODUCTION TO METABOLISM (p. 89) Most pathways can be classified as either catabolic (they degrade complex molecules to a few simple products, such as C02, NH3, and water) or anabolic (they synthesize complex end-products from simple precursors). Catabolic reactions also capture chemical energy in the form of ATP from the degradation of energy-rich molecules. Anabolic reactions require energy, which is generally provided by the breakdown of ATP. 

Dagley, S., and Nicholson, D. E. (1970) An Introduction to Metabolic Pathways. John Wiley Sons, New York. 

The PRPP amidotransferase enzyme exists as an active monomer and an inactive polymer (see "Introduction to Metabolism" Lecture). IMP, GMP and AMP all inactivate the enzyme causing a shift towards the polymerized inactive form. PRPP causes a shift towards the active monomeric form. 

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