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5: Principles of Microbial Metabolism

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    Chapter 5 BSC 3271 Learning Outcomes

    • Distinguish between catabolism and anabolism.
    • Given a metabolic pathway, determine the substrates,products, and intermediate metabolites of the pathway.
    • Describe the major characteristics of enzymes, including what kind of molecules they are, their role in the cell, and the  purpose of the enzyme's active site
    • Recognize the structure of ATP and know what kind of macromolecule it is.
    • Given a description of an ATP-generating metabolism, determine whether it is substrate-level or oxidative phosphorylation
    • Recognize the structure of NAD+/NADH, know what kind of macromolecule it is, and what it is used for in metabolism.
    • Explain why glycolysis and Krebs (TCA) cycle are considered Central Metabolism
    • Define precursor metabolite
    • Explain what products of glycolysis and the TCA (Krebs) cycle will be useful to the cell and why (in what other process(es) will they be used?).
    • Describe what happens in the 3 parts of glycolysis: energy investment, cleavage, energy generation
    • Describe the first reaction of the TCA (Krebs) cycle, including numbers of carbons in each major substrate and product involved.
    • Explain where the carbon in the carbon dioxide generated by the Krebs (TCA) cycle originally came from in an organism using glucose as its carbon and energy source.
    • Each time carbon dioxide is released during the Krebs (TCA) cycle, what else is produced?
    • Explain (generally) what is happening during the "regeneration" portion of the Krebs (TCA) cycle.
    • Identify where the following metabolites fit in to glycolysis and the Krebs (TCA) cycle: glucose, pyruvate, aceyl-CoA, citric acid, oxaloacetate, α-ketoglutarate (i.e. glycolysis or TCA; beginning, middle, end).


    • 5.1: Energy, Matter, and Enzymes
      Cellular processes such as the building or breaking down of complex molecules occur through series of stepwise, interconnected chemical reactions called metabolic pathways. The term anabolism refers to those endergonic metabolic pathways involved in biosynthesis, converting simple molecular building blocks into more complex molecules, and fueled by the use of cellular energy.
    • 5.2: Central Metabolism
      Glycolysis is the first step in the breakdown of glucose, resulting in the formation of ATP, which is produced by substrate-level phosphorylation; NADH; and two pyruvate molecules. Glycolysis does not use oxygen and is not oxygen dependent. After glycolysis, a three-carbon pyruvate is decarboxylated to form a two-carbon acetyl group, coupled with the formation of NADH. The acetyl group is attached to a large carrier compound called coenzyme A.

    Thumbnail: "File:Citric Acid Cycle Diagram.png" by Krishnabp is licensed under CC BY-SA 4.0