Metabolism

Chapter 5 Why Study Metabolism? Classification of bacteria –Oxygen Tolerance –Biochemical reactions Acids, Ammonia, Gases Fermentation Products –Food Products Yogurt, Sour Cream, Bread, Alcohol –Commercial Products Citric Acid, Plastics Environmental Cleanup

Chapter 5 Ying & Yang of Metabolism Metabolism = Anabolism + Catabolism Photosynthesis requires Respiration Respiration requires Photosynthesis Energy Production = Energy Consumption

Chapter 5 Breakdown Proteins to Amino Acids, Starch to Glucose Synthesis Amino Acids to Proteins, Glucose to Starch

Chapter 5

Overview of Metabolism Source of Energy (Photo- vs. Chemotroph) –Source of Electrons –Carrier of Electrons –Final Electron Acceptor Source of Carbon (Auto- vs. Heterotroph) –Auto- : Carbon Dioxide –Hetero- : Organic Compounds

Chapter 5 Classification based on Metabolism Where microbes get their energy? –Sunlight vs. Chemical –Photo- vs. Chemo- trophs How do they obtain carbon? –Carbon Dioxide (or inorganic cmpds.) vs. Organic Compounds (sugars, amino acids) –Auto- vs. Hetero- trophs Examples –Photoautotrophs vs. Photoheterotrophs –Chemoautotrophs vs. Chemoheterotrophs

Chapter 5

Types of -trophs

Chapter 5 Source of Electrons Autotrophs –Photosynthesis –H 2 O, H 2 S Chemotrophs –Organic Compounds –Carbohydrates (C H 2 O) Glucose, Lactose, Sucrose, Mannitol, Citrate –Amino Acids

Chapter 5 Electron Carriers Photosynthesis –NADP + H to NADPH Respiration –NAD + H to NADH –FAD + H to FADH Contain Niacin and Riboflavin –Vitamins, not stable –Can’t store these molecules

Chapter 5 Final Electron Acceptor Photosynthesis –CO 2 + H’s to CH 2 O –Stores energy Respiration –Aerobic 1/2 O 2 + H 2 to H 2 O –Anaerobic Fermentation

Chapter 5 Movement of Electrons Chemical reactions Oxidation Reactions Reduction Reactions Reactions Coupled –Redox reactions

Chapter 5

Example of Redox Equations

Chapter 5 Example of Redox Equations

Chapter 5 Example of Redox Equations

Chapter 5 Examples ATP  ADP + P –Oxidation, release energy ADP + P  ATP –Reduction, stores energy NAD + H  NADH FADH  FAD + H NH / 2 O 2  NO 2 - +H 2 O + 2H + ATP 2H 2 + O 2  2H 2 O

Chapter 5 Examples Cellular Respiration –C 6 H 12 O 6 + 6O 2  6H 2 O + 6CO ATP Photosynthesis –6H 2 O + 6CO 2 + light  C 6 H 12 O 6 + 6O 2 Nitrification –NH 4  NO 2 to NO 3 Ammonia to Nitrite to Nitrate Ammonification –N 2  NH 4

Chapter 5 Respiration Overview; – Glucose to Carbon dioxide + Water +Energy –C 6 H 12 O 6 + O 2  6CO 2 + 6H 2 O + 38 ATP –Glucose is highly reduced; contains energy –Oxygen receives the electrons to form energy 4 separate reactions –Glycolysis, Transition Reaction, Krebs Cycle, Electron Transport, Chemiosomosis Requires Oxygen

Chapter 5 Steps in Respiration Electron Donors –Organic Compounds (Glucose preferred) Electron Carriers –NAD to NADH –FAD to FADH Electron Acceptors-Terminal –O 2 to H 2 O Phosphorylation Reactions –ADP to ATP Chemiosmosis Reactions

Chapter 5 Glycolysis- 10 steps Glucose is Phosphorylated to form Fructose 1,6-diphosphate Split to form 2 Glyceraldehyde 3- phosphate Final Products are: –2 Pyruvic Acid (C 3 H 4 O 3 ) Compare to original glucose - C 6 H 12 O 6 –2 NADH –2 ATP

Chapter 5

Transition Reaction Pyruvic Acid  Acetyl - Co A + CO 2 + NADH C 2 H 4 O 2

Chapter 5 Kreb’s Cycle Figure E.3, A29 Acetyl CoA  Carbon Dioxide –C 2 H 4 O 2 to CO 2 –Energy produced/Acetyl CoA (x2 for /Glucose) 3 NADH 1 FADH 1 ATP Metabolic Wheel –Fats, amino acids, etc. enter or leave –Citrate is product of first reaction Simmons Citrate Media

Chapter 5 Electron Transport Chain NADH oxidized to NAD FAD reduced to FADH Cytochromes shuffle electrons finally to O 2 –Cytochrome Oxidase important in G - ID H 2 O formed and ATP 3 ATP / 1 NADH 2 ATP / 1 FADH

Chapter 5

Fermentation Products from Pyruvate Homolactic = Lactic Acid –Yogurt, Lactobacillus Alcohol + CO 2 Propionic Acid Butyric Acid Acetic Acid Succinic Acid Butylene to Acetoin –basis for VP Test (Vogues-Proskauer)

Chapter 5 Fermentation Products Alcohol and Carbon Dioxide –Yeast mostly Lactic Acid –Humans, muscles without oxygen –Bacteria (Lactobacillus-yogurt) Butyric Acid –Rancid butter, Clostridium-gangrene Acetoin –Butanediol fermentation in Klebsiella Propionic Acid –Swiss Cheese

Chapter 5 Fermentation in Yeast

Chapter 5 Fermentation in Muscle

Chapter 5

Photosynthesis Plants –CO 2 + H 2 O + Light  C 6 H 12 O 6 + O 2 –Water is split to release electrons Bacteria –H 2 S is used not water Sulfur or Sulfuric Acid formed Oxygen not released –Chlorophyll is different –Strict Anaerobe –Purple & Green Sulfur Bacteria

Chapter 5 Chemiosmosis Production of ATP in Electron Transport Electrochemical Gradient Formed between membranes H+ (Protons) generated from NADH Electrical Force (+) & pH Force (Acid) Gradient formed ATPase enzyme that channels H+ from High to Low concentration –3 ATP/NADH –2 ATP/NADH

Chapter 5

Summary of Respiration Aerobic Respiration –Glycolysis –Transition Rx. –Kreb’s Cycle –Electron Transport Chain Anaerobic Respiration –Pyruvate  Lactic Acid Mixed Acids Alcohol + CO 2 –Recycle NADH –2 ATP / Glucose