II. BACTERIAL GROWTH AND MICROBIAL METABOLISM

D. Cellular Respiration

4. Precursor Metabolites: Linking Catabolic and Anabolic Pathways

Fundamental statements for this learning object:

1. Catabolic pathways provide the energy that fuel anabolic pathways.
2. Precursor metabolites are intermediate molecules in catabolic and anabolic pathways that can be either oxidized to generate ATP or can be used to synthesize macromolecular subunits such as amino acids, lipids, and nucleotides.

 

Learning Objectives for this Section

Many other metabolic pathways are going on within cells in addition to those involved in energy production. Although time doesn't allow going into most of them in detail, they include the synthesis of building block molecules (amino acids, purines, pyrimidines, nucleotides, lipids, etc.), macromolecules (DNA, RNA, proteins), and cellular structures (membranes, cell walls, flagella, pili, mitochondria, chloroplasts, etc.).

Catabolic pathways provide the energy that fuel anabolic pathways. Another factor that links catabolic and anabolic pathways is the generation of precursor metabolites. Precursor metabolites (def) are intermediate molecules in catabolic and anabolic pathways that can be either oxidized to generate ATP or can be used to synthesize macromolecular subunits such as amino acids, lipids, and nucleotides as shown in Fig. 3.

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