Chapter 6 Microbial Nutrition and Metabolism 微生物学 教学课件 英文版[精品].ppt

Stage III: A second oxidation-reduction reaction occurs and fermentation products (for example, ethanol and CO2, or lactic acid) are formed.  Stage III: Production of Fermentation Products * * Glucose Fermentation: Net and Practical Results The ultimate result of glycolysis is the consumption of glucose, the net synthesis of two ATPs, and the production of fermentation products. * 6.6 Respiration and Electron Transport The discussion of respiration deals with both the carbon and electron transformations: (1) the biochemical pathways involved in the transformation of organic carbon to CO2 (2) the way electrons are transferred from the organic compound to the terminal electron acceptor, driving ATP synthesis at the expense of the proton motive force. Respiration : in which molecular oxygen or some other oxidant serves as the terminal electron acceptor * (1) to accept electrons from an electron donor and transfer them to an electron acceptor Electron Transport Electron transport systems are composed of membrane associated electron carriers. These systems have two basic functions: (2) to conserve some of the energy released during electron transfer for synthesis of ATP. * In addition, one class of nonprotein electron carriers is known, the lipid-soluble quinones. Types of oxidation-reduction enzymes involved in electron transport (1) NADH dehydrogenases (2) Riboflavin-containing electron carriers, generally called flavoproteins (3) iron-sulfur proteins (4) Cytochromes * Flavin mononucleotide (FMN) (riboflavin phosphate, a hydrogen atom carrier). The site of oxidation-reduction is the same in FMN and flavin-adeninedinucleotide (FAD). * Computer-generated model of cytochrome c. * 6.7 The Balance Sheet of Aerobic Respiration and Energy Storage Energy Storage ATP and Cell Yield * The amount of ATP produced by an organism has a direct effect on cell yield. cell yield is directly proportional to the amount of ATP produced