1 / 39

Chapter 5 Microbial Nutrition and Culture

Chapter 5 Microbial Nutrition and Culture. Siti Sarah Jumali (ext 2123) Room 3/14 sarah_jumali84@hotmail.com. Groups of bugs based on energy capture and carbon source. AUTOTROPHY : Use carbon dioxide to synthesize organic molecules Two types: Photoautotrophs : obtain energy from light

lore
Download Presentation

Chapter 5 Microbial Nutrition and Culture

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. Chapter 5 Microbial Nutrition and Culture Siti Sarah Jumali (ext 2123) Room 3/14 sarah_jumali84@hotmail.com

  2. Groups of bugs based on energy capture and carbon source • AUTOTROPHY: Use carbon dioxide to synthesize organic molecules • Two types: • Photoautotrophs: obtain energy from light • Chemoautotrophs: obtain energy from oxidizing simple inorganic substance

  3. Groups of bugs based on energy capture and carbon source cont’d • HETEROTROPHY: Get carbon dioxide from ready made organic molecules • Two types: • Photoheterotrophs: obtain chemical energy from light • Chemoheterotrophs: obtain energy from breaking down ready-made organic compounds

  4. The main types of energy capturing Metabolism

  5. Examples of Energy Source

  6. Photosynthesis and Respiration

  7. Metabolism • The sum of all chemical processes carried out by living organisms • Anabolism: rxn that requires energy in order to synthesize complex molecules from the simpler ones - (use energy and building blocks to build large molecules) • Catabolism: rxn that releases energy by breaking complex molecules into simpler ones which can be reused as building blocks - (provides energy and building blocks for anabolism)

  8. Metabolism: The sum of catabolism and anabolism Catabolism Energy Anabolism

  9. Metabolic Pathway • Glycolisis, fermentation, aerobic respiration and photosynthesis each consists of a series of chemical reaction • The product of one reaction serves as the substrate for the next: ABCD • Such chain of reactions is called a metabolic pathway: - Anabolic pathways make the complex molecules that form structure of cells, enzymes and molecules that control cells - Catabolic pathways capture energy in a form a cell can use

  10. Oxidation-Reduction Reactions • All catabolic reactions involve electron transfer which is directly related to oxidation and reduction (redox potential) • Redox reaction: An oxidation reaction paired with a reduction reaction - Oxidation: the loss of removal of electrons -Reduction: the gain of electrons

  11. Oxidation-Reduction Reactions

  12. Representative Biological Oxidations Acronyms for oxidation and reduction: • Oxidation Is Losing Electrons, Reduction Is Gaining Electrons: OIL RIG • Losing Electrons Oxidation, Gaining Electrons Reduction: LEO the lion. GER! or LEO says GER • Electron Loss Means Oxidation: ELMO In biological systems, the electrons are often associated with hydrogen atoms. Biological oxidations are often dehydrogenation.

  13. Metabolic Pathways of Energy Production

  14. Metabolic Pathways of Energy Production (b)

  15. Energy Transfer by Carrier Molecules • Carrier molecules such as Cytochrome (cyt) and some coenzymes carry energy in the form of electrons in many biochemical reactions • Coenzymes such as FAD carry whole hydrogen atoms (electrons together with protons); NAD carries one hydrogen atom and one “naked” electron • When co-enzymes are reduced, they increase in energy, when they are oxidized, they decrease in energy.

  16. Energy Generation of ATP • ATP is generated by the phosphorylation of ADP ADP + Pi + Energy ATP • In cells, energy is provided by the hydrolysis of ATP ATP ADP + Pi + Energy Energy Energy

  17. Generation of ATP • Substrate level Phosphorylation: Energy from the transfer of a high energy PO4 to ADP generates ATP C-C-C-P + ADP C-C-C + ATP • Oxidative Phosphorylation: Energy relseased from transfer of electrons (oxidation) of one compound to another (reduction) is used to generate Atp in the electron transport chain • Photophosporylation: Light causes chlorophyll to give up electrons. Energy released from transfer of electrons (oxidation) of chlorophyll trough a system of carrier molecules is used to generate ATP

  18. Overview of Respiration vs Fermentation

  19. Carbohydrate Catabolism • The breakdown of carbohydrate to release energy involves • Glycolisis (cytoplasm) • Krebs cycle (mitochondrion) • Electron transport chain

  20. Glycolysis • Glycolysis (Embden Meyerhof pathway) is the metabolic pathway used by most autotrophic and heterotrophic organismsm to begin breakdown of glucose • Does not require oxygen, but occur in precense or absence of oxygen • Overall chemical reaction of Glycolysis

  21. Glycolysis: Oxidation of Glucose 2ATP 2 NAD+ 2ADP 2NADH + 2H+ 4 ADP 4 ATP Glucose two Glyceraldehyde-3-PO4 two Pyruvate

  22. Glycolysis: Oxidation of Glucose

  23. Glycolysis: Oxidation of Glucose 2 NAD+ 2 NADH + 2 H+

  24. Glycolysis: Oxidation of Glucose Glycolysis generates 2 ATP molecules and 2 NADH + 2 H+ Two ATP used in adding phosphate groups to glucose and fructose-6-phosphate (- 2 ATP) Four ATP generated in direct transfer to ADP by two 3-C molecules (+ 4 ATP) Glucose + 2 ADP + 2 Pi + 2 NAD+ 2pyruvate + 2 ATP + 2 NADH + 2 H+

  25. Pathways for Pyruvate Aerobic conditions O || CH3–C –COO- + NAD+ + CoA pyruvate O || CH3–C –CoA + CO2 + NADH + H+ acetyl CoA

  26. Pathways for Pyruvate Anaerobic conditions(No O2 available) Reduce to lactate to replenish NAD+ for glycolysis O OH || | CH3–C –COO- + NADH + H+ CH3–CH –COO- + NAD+ pyruvate lactate enzyme: lactate dehydrogenase

  27. Glycolysis

  28. Alternative to Glycolysis • Pentose phosphate pathway • Uses pentoses and NADPH • Operates with glycolisis • Entner-Doudoroff pathway • Produces NADPH and ATP • Does not involve glycolisis • Pseudomonas, Rhizobium, Agrobacterium

  29. Intermediate step • Pyruvic acid (from glycolysis) is oxidized and decarboxylated

  30. The Krebs Cycle/ The Citric acid cycle (TCA cycle) • Oxidation of acetyl Co-A produces NADH and FADH2 (mitochondrion)

  31. The Electron Transport Chain • An electron transport chain (ETC) couples electron transfer between an electron donor (such as NADH) and an electron acceptor (such as O2) to the transfer of H+ ions (protons) across a membrane. • A series of oxidation-reduction reactions, the electron transport chain (ETC) performs 2 basic functions: • Accepting electrons from an electron donor and transferring them to an electron acceptor • Conserving for ATP synthesis some of the energy released during the electron transfer • A series of carrier molecules that are, in turn oxidized and reduced as electrons are passed down the chain • Energy released can be used to produce ATP by chemiosmosis

  32. The Electron Transport Chain

  33. The Electron Transport Chain

  34. Chemiosmosis • Electrons from the hydrogen atoms removed from the reactions of the Krebs cycle are transferred through the electron transport system • Electron transport creates the H potential across the membrane • Combination of hydrogen/electron carriers

  35. Chemiosmosis

  36. Chemiosmosis

  37. Questions?

More Related