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  • Metabolism
  • Oxidation-reduction or redox reactions
  • Enzyme Classification Based on Reaction Types
  • Makeup of a protein enzyme
  • Representative Cofactors of Enzymes
  • Effect of enzymes on chemical reactions
  • Enzymes fitted to substrates-overview
  • The process of enzymatic activity
  • Effects of temperature, pH, and substrate concentration on enzyme activity
  • Denaturation of protein enzymes
  • Competitive inhibition of enzyme activity
  • Allosteric control of enzyme activity
  • Feedback inhibition-overview
  • Summary of glucose catabolism
  • Glycolysis-overview
  • Substrate-level phosphorylation
  • Pentose phosphate pathway
  • Entner-Douoroff pathway
  • Formation of acetyl-CoA
  • The Krebs cycle
  • An electron transport chain
  • One possible arrangement of an electron transport chain
  • Summary of Ideal Prokaryotic Aerobic Respiration
  • Fermentation
  • Comparison of Aerobic Respiration, Anaerobic Respiration, and Fermentation
  • Representative fermentation products and the organisms that produce them
  • Catabolism of a fat molecule-overview
  • Protein catabolism in microbes
  • Photosynthetic structures in a prokaryote
  • Reaction center of a photosystem
  • Photosynthesis: photophosphorylation-overview
  • A Comparison of the Three Types of Phosphorylation
  • Simplified diagram of the Calvin-Benson cycle
  • The Twelve Precursor Metabolites
  • Role of gluconeogenesis in the biosynthesis of complex carbohydrates
  • Biosynthesis of fat
  • Synthesis of amino acids via amination and transamination
  • Biosynthesis of nucleotides
  • Integration of cellular metabolism
  • Start here_ch05_lecture

    1. 1. Chapter 5 Microbial Metabolism
    2. 2. Basic Chemical Reactions Underlying Metabolism <ul><li>Metabolism </li></ul><ul><ul><li>Collection of controlled biochemical reactions that take place within cells of an organism </li></ul></ul><ul><ul><li>Ultimate function of metabolism is to reproduce the organism </li></ul></ul>
    3. 3. Basic Chemical Reactions Underlying Metabolism <ul><li>Metabolic Processes Guided by Eight Elementary Statements </li></ul><ul><ul><li>Every cell acquires nutrients </li></ul></ul><ul><ul><li>Metabolism requires energy from light or from catabolism of nutrients </li></ul></ul><ul><ul><li>Energy is stored in adenosine triphosphate (ATP) </li></ul></ul><ul><ul><li>Cells catabolize nutrients to form precursor metabolites </li></ul></ul><ul><ul><li>Precursor metabolites, energy from ATP, and enzymes are used in anabolic reactions </li></ul></ul><ul><ul><li>Enzymes plus ATP form macromolecules </li></ul></ul><ul><ul><li>Cells grow by assembling macromolecules </li></ul></ul><ul><ul><li>Cells reproduce once they have doubled in size </li></ul></ul>
    4. 4. Basic Chemical Reactions Underlying Metabolism Animation: Microbial Metabolism: Metabolism: Overview
    5. 5. Basic Chemical Reactions Underlying Metabolism <ul><li>Catabolism and Anabolism </li></ul><ul><ul><li>Two major classes of metabolic reactions </li></ul></ul><ul><ul><li>Catabolic pathways break larger molecules into smaller products; they are exergonic (release energy) </li></ul></ul><ul><ul><li>Anabolic pathways synthesize large molecules from the smaller products of catabolism; they are endergonic (require more energy than they release) </li></ul></ul>
    6. 6. Basic Chemical Reactions Underlying Metabolism [INSERT FIGURE 5.1]
    7. 7. Basic Chemical Reactions Underlying Metabolism <ul><li>Oxidation and Reduction Reactions </li></ul><ul><ul><li>Transfer of electrons from molecule that donates an electron to a molecule that accepts an electron </li></ul></ul><ul><ul><li>Reactions always occur simultaneously </li></ul></ul><ul><ul><li>Cells use electron carrier molecules to carry electrons (often in H atoms) </li></ul></ul><ul><ul><li>Three important electron carriers </li></ul></ul><ul><ul><ul><li>Nicotinamide adenine dinucleotide (NAD + ) </li></ul></ul></ul><ul><ul><ul><li>Nicotinamide adenine dinucleotide phosphate (NADP + ) </li></ul></ul></ul><ul><ul><ul><li>Flavine adenine dinucleotide (FAD) -> FADH2 </li></ul></ul></ul>
    8. 8. Basic Chemical Reactions Underlying Metabolism [INSERT FIGURE 5.2]
    9. 9. Basic Chemical Reactions Underlying Metabolism Animation: Microbial Metabolism: Oxidation-Reduction Reactions
    10. 10. Basic Chemical Reactions Underlying Metabolism <ul><li>ATP Production and Energy Storage </li></ul><ul><ul><li>Organisms release energy from nutrients; can be concentrated and stored in high-energy phosphate bonds of ATP </li></ul></ul><ul><ul><li>Phosphorylation – organic phosphate is added to substrate </li></ul></ul><ul><ul><li>Cells phosphorylate ADP to ATP in three ways </li></ul></ul><ul><ul><ul><li>Substrate-level phosphorylation </li></ul></ul></ul><ul><ul><ul><li>Oxidative phosphorylation </li></ul></ul></ul><ul><ul><ul><li>Photophosphorylation </li></ul></ul></ul><ul><ul><li>Anabolic pathways use some energy of ATP by breaking a phosphate bond </li></ul></ul>
    11. 11. Basic Chemical Reactions Underlying Metabolism <ul><li>The Roles of Enzymes in Metabolism </li></ul><ul><ul><li>Naming and classifying enzymes </li></ul></ul><ul><ul><ul><li>Enzymes are organic catalysts – increase the likelihood of a reaction but are not permanently changed </li></ul></ul></ul><ul><ul><ul><li>Six categories of enzymes based on mode of action </li></ul></ul></ul><ul><ul><ul><ul><li>Hydrolases </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Isomerases </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Ligases or polymerases </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Lyases </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Oxidoreductases </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Transferases </li></ul></ul></ul></ul>
    12. 12. Basic Chemical Reactions Underlying Metabolism [INSERT TABLE 5.1]
    13. 13. Basic Chemical Reactions Underlying Metabolism Animation: Microbial Metabolism: Enzymes: Overview
    14. 14. Basic Chemical Reactions Underlying Metabolism <ul><li>The Roles of Enzymes in Metabolism </li></ul><ul><ul><li>Makeup of enzymes </li></ul></ul><ul><ul><ul><li>Many protein enzymes are complete in themselves </li></ul></ul></ul><ul><ul><ul><li>Others are composed of protein portions (apoenzymes) that are inactive if not bound to non-protein cofactors (inorganic ions or coenzymes) </li></ul></ul></ul><ul><ul><ul><li>Binding of apoenzyme and its cofactor(s) yields holoenzyme </li></ul></ul></ul><ul><ul><ul><li>Some are RNA molecules called ribozymes </li></ul></ul></ul>
    15. 15. Basic Chemical Reactions Underlying Metabolism [INSERT FIGURE 5.3]
    16. 16. Basic Chemical Reactions Underlying Metabolism [INSERT TABLE 5.2]
    17. 17. Basic Chemical Reactions Underlying Metabolism [INSERT FIGURE 5.4]
    18. 18. Basic Chemical Reactions Underlying Metabolism [INSERT FIGURE 5.5]
    19. 19. Basic Chemical Reactions Underlying Metabolism [INSERT FIGURE 5.6]
    20. 20. Basic Chemical Reactions Underlying Metabolism Animation: Microbial Metabolism: Enzymes: Steps in a Reaction
    21. 21. Basic Chemical Reactions Underlying Metabolism <ul><li>The Roles of Enzymes in Metabolism </li></ul><ul><ul><li>Enzyme activity </li></ul></ul><ul><ul><ul><li>Many factors influence the rate of enzymatic reactions </li></ul></ul></ul><ul><ul><ul><ul><li>Temperature </li></ul></ul></ul></ul><ul><ul><ul><ul><li>pH </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Enzyme and substrate concentrations </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Presence of inhibitors </li></ul></ul></ul></ul><ul><ul><ul><li>Inhibitors </li></ul></ul></ul><ul><ul><ul><ul><li>Substances that block an enzyme’s active site </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Do not denature enzymes </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Three types </li></ul></ul></ul></ul>
    22. 22. Basic Chemical Reactions Underlying Metabolism [INSERT FIGURE 5.7]
    23. 23. Basic Chemical Reactions Underlying Metabolism [INSERT FIGURE 5.8]
    24. 24. Basic Chemical Reactions Underlying Metabolism [INSERT FIGURE 5.9]
    25. 25. Basic Chemical Reactions Underlying Metabolism Animation: Microbial Metabolism: Enzymes: Competitive Inhibition
    26. 26. Basic Chemical Reactions Underlying Metabolism [INSERT FIGURE 5.10]
    27. 27. Basic Chemical Reactions Underlying Metabolism Animation: Microbial Metabolism: Enzymes: Noncompetitive Inhibition
    28. 28. Basic Chemical Reactions Underlying Metabolism [INSERT FIGURE 5.11]
    29. 29. Carbohydrate Catabolism <ul><li>Many organisms oxidize carbohydrates as the primary energy source for anabolic reactions </li></ul><ul><li>Glucose most common carbohydrates used </li></ul><ul><li>Glucose catabolized by </li></ul><ul><ul><li>Cellular respiration </li></ul></ul><ul><ul><li>Fermentation </li></ul></ul>
    30. 30. Carbohydrate Catabolism [INSERT FIGURE 5.12]
    31. 31. Carbohydrate Catabolism <ul><li>Glycolysis </li></ul><ul><ul><li>Occurs in cytoplasm of most cells </li></ul></ul><ul><ul><li>Involves splitting of a six-carbon glucose into two three-carbon sugar molecules </li></ul></ul><ul><ul><li>Direct transfer of phosphate between two substrates occurs four times – substrate = level phosphorylation </li></ul></ul><ul><ul><li>Net gain of two ATP molecules, two molecules of NADH, and precursor metabolite pyruvic acid </li></ul></ul>
    32. 32. Carbohydrate Catabolism Animation: Microbial Metabolism: Glycolysis: Overview
    33. 33. Carbohydrate Catabolism <ul><li>Glycolysis </li></ul><ul><ul><li>Divided into three stages involving ten total steps </li></ul></ul><ul><ul><ul><li>Energy-investment stage </li></ul></ul></ul><ul><ul><ul><li>Lysis stage </li></ul></ul></ul><ul><ul><ul><li>Energy-conserving stage </li></ul></ul></ul>
    34. 34. Carbohydrate Catabolism [INSERT FIGURE 5.13]
    35. 35. Carbohydrate Catabolism Animation: Microbial Metabolism: Glycolysis: Steps
    36. 36. Carbohydrate Catabolism [INSERT FIGURE 5.14]
    37. 37. Carbohydrate Catabolism <ul><li>Alternatives to Glycolysis </li></ul><ul><ul><li>Yield fewer molecules of ATP than glycolysis </li></ul></ul><ul><ul><li>Reduce coenzymes and yield different metabolites needed in anabolic pathways </li></ul></ul><ul><ul><li>Two pathways </li></ul></ul><ul><ul><ul><li>Pentose phosphate pathway – net gain of two molecules of NADPH, one molecule of ATP, and five-carbon precursor metabolites </li></ul></ul></ul><ul><ul><ul><li>Entner-Doudoroff pathway – net gain of two molecules of NADPH, one molecule of ATP, and precursor metabolites </li></ul></ul></ul>
    38. 38. Carbohydrate Catabolism [INSERT FIGURE 5.15]
    39. 39. Carbohydrate Catabolism
    40. 40. Carbohydrate Catabolism <ul><li>Continuation of Cellular Respiration </li></ul><ul><ul><li>Resultant pyruvic acid completely oxidized to produce ATP by a series of redox reactions </li></ul></ul><ul><ul><li>Three stages of cellular respiration </li></ul></ul><ul><ul><li>1. Synthesis of acetyl-CoA </li></ul></ul><ul><ul><li>2. Krebs cycle </li></ul></ul><ul><ul><li>3. Final series of redox reactions (electron transport chain) </li></ul></ul>
    41. 41. Carbohydrate Catabolism [INSERT FIGURE 5.17]
    42. 42. Carbohydrate Catabolism <ul><li>Continuation of Cellular Respiration </li></ul><ul><ul><li>Synthesis of acetyl-CoA </li></ul></ul><ul><ul><ul><li>Results in </li></ul></ul></ul><ul><ul><ul><ul><li>Two molecules of acetyl-CoA </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Two molecules of CO 2 </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Two molecules of NADH </li></ul></ul></ul></ul>
    43. 43. Carbohydrate Catabolism <ul><li>Continuation of Cellular Respiration </li></ul><ul><ul><li>The Krebs cycle </li></ul></ul><ul><ul><ul><li>Great amount of energy remains in bonds of acetyl-CoA </li></ul></ul></ul><ul><ul><ul><li>The Krebs cycle transfers much of this energy to coenzymes NAD + and FAD </li></ul></ul></ul><ul><ul><ul><li>Occurs in cytoplasm of prokaryotes and in matrix of mitochondria in eukaryotes </li></ul></ul></ul>
    44. 44. Carbohydrate Catabolism <ul><li>Continuation of Cellular Respiration </li></ul><ul><ul><li>The Krebs cycle </li></ul></ul><ul><ul><ul><li>Six types of reactions in Krebs cycle </li></ul></ul></ul><ul><ul><ul><ul><li>Anabolism of citric acid </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Isomerization reactions </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Hydration reaction </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Redox reactions </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Decarboxylations </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Substrate-level phosphorylation </li></ul></ul></ul></ul>
    45. 45. Carbohydrate Catabolism [INSERT FIGURE 5.18]
    46. 46. Carbohydrate Catabolism Animation: Microbial Metabolism: Krebs Cycle—Overview
    47. 47. Carbohydrate Catabolism Animation: Microbial Metabolism: Krebs Cycle— Steps
    48. 48. Carbohydrate Catabolism <ul><li>Continuation of Cellular Respiration </li></ul><ul><ul><li>The Krebs cycle </li></ul></ul><ul><ul><ul><li>Results in </li></ul></ul></ul><ul><ul><ul><ul><li>Two molecules of ATP </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Two molecules of FADH 2 </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Six molecules of NADH </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Four molecules of CO 2 </li></ul></ul></ul></ul>
    49. 49. Carbohydrate Catabolism <ul><li>Continuation of Cellular Respiration </li></ul><ul><ul><li>Electron transport </li></ul></ul><ul><ul><ul><li>Most significant production of ATP occurs through stepwise release of energy from series of redox reactions known as an electron transport chain (ETC) </li></ul></ul></ul><ul><ul><ul><li>Consists of series of membrane-bound carrier molecules that pass electrons from one to another and ultimately to final electron acceptor </li></ul></ul></ul><ul><ul><ul><li>Energy from electrons used to pump protons (H + ) across the membrane, establishing a proton gradient </li></ul></ul></ul><ul><ul><ul><li>Located in cristae of eukaryotes and in cytoplasmic membrane of prokaryotes </li></ul></ul></ul>
    50. 50. Carbohydrate Catabolism [INSERT FIGURE 5.19]
    51. 51. Carbohydrate Catabolism Animation: Microbial Metabolism: Electron Transport Chain: Overview
    52. 52. Carbohydrate Catabolism <ul><li>Continuation of Cellular Respiration </li></ul><ul><ul><li>Electron transport </li></ul></ul><ul><ul><ul><li>Four categories of carrier molecules </li></ul></ul></ul><ul><ul><ul><ul><li>Flavoproteins </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Ubiquinones </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Metal-containing proteins </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Cytochromes </li></ul></ul></ul></ul><ul><ul><ul><li>Some organisms can vary their carrier molecules under different environmental conditions </li></ul></ul></ul><ul><ul><ul><li>In aerobic respiration oxygen serves as final electron acceptor to yield water </li></ul></ul></ul><ul><ul><ul><li>In anaerobic respiration molecules other than oxygen serve as final electron acceptor </li></ul></ul></ul>
    53. 53. Carbohydrate Catabolism [INSERT FIGURE 5.20]
    54. 54. Carbohydrate Catabolism Animation: Microbial Metabolism: Electron Transport Chain: The Process
    55. 55. Carbohydrate Catabolism Animation: Microbial Metabolism: Electron Transport Chain: Factors Affecting ATP Yield
    56. 56. Carbohydrate Catabolism <ul><li>Continuation of Cellular Respiration </li></ul><ul><ul><li>Chemiosmosis </li></ul></ul><ul><ul><ul><li>Membrane maintains electrochemical gradient by keeping one or more chemicals in higher concentration on one side </li></ul></ul></ul><ul><ul><ul><li>Cells use energy released in redox reactions of ETC to create proton gradient, which has potential energy known as proton motive force </li></ul></ul></ul><ul><ul><ul><li>Protons, propelled by proton motive force, flow down electrochemical gradient through ATP synthases (protein channels) that phosphorylate ADP to ATP </li></ul></ul></ul><ul><ul><ul><li>Called oxidative phosphorylation because proton gradient created by oxidation of components of ETC </li></ul></ul></ul><ul><ul><ul><li>Total of ~34 ATP molecules formed from one molecule of glucose </li></ul></ul></ul>
    57. 57. Carbohydrate Catabolism [INSERT TABLE 5.3]
    58. 58. Carbohydrate Catabolism <ul><li>Fermentation </li></ul><ul><ul><li>Sometimes cells cannot completely oxidize glucose by cellular respiration </li></ul></ul><ul><ul><li>Cells require constant source of NAD + that cannot be obtained by simply using glycolysis and the Krebs cycle </li></ul></ul><ul><ul><ul><li>In respiration, electron transport regenerates NAD + from NADH </li></ul></ul></ul><ul><ul><li>Fermentation pathways provide cells with alternate source of NAD + </li></ul></ul><ul><ul><ul><li>Partial oxidation of sugar (or other metabolites) to release energy using an organic molecule from within the cell as an electron acceptor </li></ul></ul></ul>
    59. 59. Carbohydrate Catabolism [INSERT FIGURE 5.21]
    60. 60. Carbohydrate Catabolism [INSERT TABLE 5.4]
    61. 61. Carbohydrate Catabolism [INSERT FIGURE 5.22]
    62. 62. Carbohydrate Catabolism Animation: Microbial Metabolism: Fermentation
    63. 63. Other Catabolic Pathways <ul><li>Lipid Catabolism </li></ul><ul><li>Protein Catabolism </li></ul>
    64. 64. Other Catabolic Pathways [INSERT FIGURE 5.23]
    65. 65. Other Catabolic Pathways [INSERT FIGURE 5.24]
    66. 66. Photosynthesis <ul><li>Every food chain begins with anabolic pathways in organisms that synthesize their own organic molecules from inorganic carbon dioxide </li></ul><ul><li>Most of these organisms capture light energy from the sun and use it to drive the synthesis of carbohydrates from CO 2 and H 2 O by a process called photosynthesis </li></ul>
    67. 67. Photosynthesis Animation: Microbial Metabolism: Photosynthesis: Overview
    68. 68. Photosynthesis <ul><li>Chemicals and Structures </li></ul><ul><ul><li>Chlorophylls </li></ul></ul><ul><ul><ul><li>Most important of organisms that capture light energy with pigment molecules </li></ul></ul></ul><ul><ul><li>Composed of hydrocarbon tail attached to light-absorbing active site centered around magnesium ion </li></ul></ul><ul><ul><ul><ul><li>Active sites structurally similar to cytochrome molecules in ETC </li></ul></ul></ul></ul><ul><li>Vary slightly in lengths and structures of hydrocarbon tails and in atoms that extend from active site </li></ul><ul><li>They subsequently absorb light of different wavelengths </li></ul>
    69. 69. Photosynthesis <ul><li>Chemicals and Structures </li></ul><ul><ul><li>Cells arrange molecules of chlorophyll and other pigments in protein matrix to form light-harvesting matrices called photosystems </li></ul></ul><ul><ul><li>Embedded in cellular membranes called thylakoids </li></ul></ul><ul><ul><ul><li>In prokaryotes – invagination of cytoplasmic membrane </li></ul></ul></ul><ul><ul><ul><li>In eukaryotes – formed from infoldings of inner membrane of chloroplasts </li></ul></ul></ul><ul><ul><ul><ul><li>Arranged in stacks called grana </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Stroma is space between outer membrane of grana and thylakoid membrane </li></ul></ul></ul></ul>
    70. 70. Photosynthesis [INSERT FIGURE 5.25]
    71. 71. Photosynthesis <ul><li>Chemicals and Structures </li></ul><ul><ul><li>Two types of photosystems </li></ul></ul><ul><ul><ul><li>Photosystem I (PS I) </li></ul></ul></ul><ul><ul><ul><li>Photosystem II (PS II) </li></ul></ul></ul><ul><ul><li>Photosystems absorb light energy and use redox reactions to store energy in the form of ATP and NADPH </li></ul></ul><ul><ul><li>Classified as light-dependent reactions because they depend on light energy </li></ul></ul><ul><ul><li>Light-independent reactions synthesize glucose from carbon dioxide and water </li></ul></ul>
    72. 72. Photosynthesis <ul><li>Light-Dependent Reactions </li></ul><ul><ul><li>As electrons move down the chain, their energy is used to pump protons across the membrane </li></ul></ul><ul><ul><li>Photophosphorylation uses proton motive force to generate ATP </li></ul></ul><ul><ul><li>Photophosphorylation can be cyclic or noncyclic </li></ul></ul>
    73. 73. Photosynthesis [INSERT FIGURE 5.26]
    74. 74. Photosynthesis [INSERT FIGURE 5.27]
    75. 75. Photosynthesis Animation: Microbial Metabolism: Photosynthesis: Cyclic Photophosphorylation
    76. 76. Photosynthesis Animation: Microbial Metabolism: Photosynthesis: Noncyclic Photophosphorylation
    77. 77. Photosynthesis [INSERT TABLE 5.5]
    78. 78. Photosynthesis <ul><li>Light-Independent Reactions </li></ul><ul><ul><li>Do not require light directly, but use ATP and NADPH generated by light-dependent reactions </li></ul></ul><ul><ul><li>Key reaction is carbon fixation by Calvin-Benson cycle </li></ul></ul><ul><ul><ul><li>For every three molecules of CO 2 that enter the cycle, one molecule of glyceraldehyde 3-phosphate leaves </li></ul></ul></ul><ul><ul><ul><li>For every two molecules of glyceraldehyde 3-phosphate, one molecule of glucose 6-phosphate is anabolically synthesized by glycolysis </li></ul></ul></ul>
    79. 79. Photosynthesis [INSERT FIGURE 5.28]
    80. 80. Photosynthesis Animation: Microbial Metabolism: Photosynthesis: Light-Independent Reactions
    81. 81. Other Anabolic Pathways <ul><li>Anabolic reactions are synthesis reactions requiring energy and a source of metabolites </li></ul><ul><li>Energy derived from ATP from catabolic reactions </li></ul><ul><li>Glycolysis, the Krebs cycle, and the pentose phosphate pathway provide twelve basic precursor metabolites from which all macromolecules and cellular structures are made </li></ul><ul><li>Many anabolic pathways are the reversal of the catabolic pathways </li></ul><ul><ul><li>Reactions that can proceed in either direction are amphibolic </li></ul></ul>
    82. 82. Other Anabolic Pathways [INSERT TABLE 5.6]
    83. 83. Other Anabolic Pathways [INSERT FIGURE 5.29]
    84. 84. Other Anabolic Pathways [INSERT FIGURE 5.30]
    85. 85. Other Anabolic Pathways [INSERT FIGURE 5.31]
    86. 86. Other Anabolic Pathways [INSERT FIGURE 5.32]
    87. 87. Integration and Regulation of Metabolic Function <ul><li>Cells synthesize or degrade channel and transport proteins </li></ul><ul><li>Cells often synthesize enzymes needed to catabolize a particular substrate only when that substrate is available </li></ul><ul><li>If two energy sources are available, cells catabolize the more energy efficient of the two first. </li></ul><ul><li>Cells synthesize the metabolites they need, but typically cease synthesis if metabolite is available </li></ul>
    88. 88. Integration and Regulation of Metabolic Function <ul><li>Eukaryotic cells keep metabolic processes from interfering with each other by isolating particular enzyme within membrane-bounded organelles </li></ul><ul><li>Cells use allosteric sites on enzymes to control the activity of enzymes </li></ul><ul><li>Feedback inhibition slows or stops anabolic pathways when product is in abundance </li></ul><ul><li>Cells regulate amphibolic pathways that use the same substrate by requiring different coenzymes for each pathway </li></ul>
    89. 89. Integration and Regulation of Metabolic Function <ul><li>Two types of regulatory mechanisms </li></ul><ul><ul><li>Control of gene expression </li></ul></ul><ul><ul><ul><li>Cells control amount and timing of protein (enzyme) production </li></ul></ul></ul><ul><ul><li>Control of metabolic expression </li></ul></ul><ul><ul><ul><li>Cells control activity of proteins (enzymes) once produced </li></ul></ul></ul>
    90. 90. Integration and Regulation of Metabolic Function [INSERT FIGURE 5.33]
    91. 91. Integration and Regulation of Metabolic Function Animation: Microbial Metabolism: Metabolism: The Big Picture

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