Citric acid cycle summary

In summary, I have provided two examples of catabolic metabolic pathways linked to prodnction of ATP glycolysis, in which glucose is converted to lactate and pyrnvate and the citric acid cycle, in which acetate (derived from pyrnvate) is converted to carbon dioxide and water. In fact, these and other catabolic pathways generate more molecnles of ATP than 1 have so far let on. Now we need to do two things qnantitate the actnal yields of ATP and say something about how they are created. We begin by directing attention to the mitochondria. 

In addition to its role in energy production, the citric acid cycle plays another important role in metabolism. Cycle intermediates are substrates in a variety of biosynthetic reactions. Table 9.2 provides a summary of the roles of coenzymes in the citric acid cycle. 

Enzymes / Intermediates / Summary / of the citric acid cycle... 

Regulation of the Pyruvate Dehydrogenase Complex Control of the Citric Acid Cycle (Figure 14.3) (Summary)... 

FIGURE 19.10 a summary of catabolism, showing the central role of the citric acid cycle. Note that the end products of the catabolism of carbohydrates, lipids, and amino acids all appear. (PEP is phosphoenolpyruvate a-KG is a-ketoglutarate TA is transamination > > > is a multistep pathway.)... 

Bodner, C. M. The Tricarboxylic Acid (TCA), Citric Acid, or Krebs Cycle. / Chem. Ed. 63, 673-677 (1986). [A concise and well-written summary of the citric acid cycle. Part of a series on metabolism.]... 

The citric acid cycle, also known as the tricarboxylic acid cycle or the Krebs cycle, is the final oxidative pathway for carbohydrates, lipids, and amino acids. It is also a source of precursors for biosynthesis. The authors begin Chapter 17 with a detailed discussion of the reaction mechanisms of the pyruvate dehydrogenase complex, followed by a description of the reactions of the citric acid cycle. This description includes details of mechanism and stereospecificity of some of the reactions, and homologies of the enzymes to other proteins. In the following sections, they describe the stoichiometry of the pathway including the energy yield (ATP and GTP) and then describe control mechanisms. They conclude the chapter with a summary of the biosynthetic roles of the citric acid cycle and its relationship to the glyoxylate cycle found in bacteria and plants. 

Summary of Products from the Citric Acid Cycle... 

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