1 / 35

Microbial Metabolism

Microbial Metabolism. Microbial Metabolism. The sum of all chemical reactions within a living organism Catabolism Anabolism. Catabolism. Destructive metabolism ; the breaking down in living organisms of more complex substances into simpler ones, with the release of energy

zody
Download Presentation

Microbial Metabolism

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Microbial Metabolism

  2. Microbial Metabolism • The sum of all chemical reactions within a living organism • Catabolism • Anabolism

  3. Catabolism Destructive metabolism; the breaking down in living organisms of more complex substances into simpler ones, with the release of energy (opposed to anabolism)

  4. CO2 + H2O + Energy Catabolism • Complex substances into simple ones, releases energy Glucose

  5. Catabolism Peptide Single amino acids Protein Energy

  6. Anabolism Constructive metabolism; the synthesis in living organisms of more complex substances from simpler ones, spending energy (opposed to catabolism )

  7. Amino acids + Energy Proteins Anabolism • Simple substances into complex ones, spend energy

  8. Anabolism Peptide Enzyme Energy Single amino acids Protein

  9. Enzymes • Speed up chemical reactions • Increase frequency of collision • Orient molecules • Lower activation energy • Low temperatures

  10. Enzymes (cont.) • Very efficient • Reactions occur 10 billion times faster than without enzyme • Enzyme does not change during reaction

  11. Substrate • Substance that the enzyme acts on (i.e.. Sucrose) sucrose + sucrase=glucose & fructose substrate+enzyme=product(s)

  12. Enzyme structure • three-dimensional shape (thousands of shapes) • lock and key complementary

  13. Enzyme structure Substrate Product Processing Enzyme Active site

  14. Turnover number • Maximum number of substrate molecules that one enzyme can process per second • 1 to 10,000, but may be as high as 500,000

  15. Enzyme cellular control • Repression • Induction

  16. Repression • Mechanism that inhibits the synthesis of an enzyme when the specific-end product is present in abundance, or the substrateis absent

  17. Induction • Mechanism that promotes the synthesis of an enzyme when the specific-end product is present in low concentration, or absent, and the substrateis present

  18. Repression/induction Lactose present B-galactosidase Glucose and galactose (end products) high concentration

  19. End-product and enzyme b-galactosidase (enzyme) Glucose and galactose (end products) Concentration Time

  20. Substrate and enzyme B-galactosidase Lactose (substrate) Concentration Time

  21. Substrate and enzyme B-galactosidase Lactose (substrate) Concentration Time

  22. Cofactors • Metal ions (Fe, Cu, Mg, Zn, Ca and Co) • Bridge between substrate and enzyme • Coenzymes • Derived from vitamins (B-vitamins) • Electron carriers (NAD+ & NADP+)

  23. Factors Influencing Enzymatic Activity • Temperature • pH • Inhibitors • Cyanide, arsenic, mercury

  24. Energy Production • Adenosine triphosphate (ATP) • Cell’s energy carrier • Mitochondria (eucaryotes) • Plasma membrane (bacteria)

  25. Respiration in eucaryotes Mitochondria Cell membrane Respiration in procaryotes (bacteria)

  26. Oxidation-Reduction (Redox reactions) • Highly reduced compounds (many Hydrogens) are high in energy (glucose) • Highly oxidized compounds are low in energy (CO2)

  27. Oxidation-Reduction (Redox reactions) (cont.) • Glucose (C6H12O6), reduced, high energy • CO2, oxidized, low energy

  28. Glucose • Respiration (O2 or inorganic substances as electron acceptors) • Fermentation (organic substances as electron acceptors)

  29. Glycolysis • First step in carbohydrate catabolism in both, respiration and fermentation • Does not require oxygen • 10 different reactions (enzymes)

  30. Glycolysis Glucose -C-C-C-C-C-C - Oxidation Pyruvic acid -C-C-C- -C-C-C -

  31. Glycolysis (cont.) • ATPs’ produced 4 • ATPs’ consumed 2 2

  32. Pyruvic acid C-C-C (2) Oxidation Krebs cycle 6CO2 + 6H2O + 38 ATP (pro) 36 ATP (eu) Aerobic Respiration • O2required

  33. Anaerobic respiration • Electron acceptor is an inorganic substance other than O2 (number of ATPs varies) NO3--->NO2 SO4---> H2S CO3--->CH4

  34. Fermentation • e- acceptor is an organic substance (pyruvate) • Products • Energy • Lactic acid • Alcohol

  35. Fermentation Glucose 2 Lactic acid 2 ATP

More Related