1. Chapter 5: Microbial Metabolism

2. METABOLISM Sum of all chemical rxn’s within a living organism Release energy Require energy

3. CATABOLIC REACTION (degradative) Breakdown of complex organic compounds into simpler ones Generally hydrolytic reactions (water used to break bonds) Exergonic (produce more energy than consume) Provide building blocks for anabolic rxns and energy needed to drive anabolic rxns ANABOLIC REACTIONS (biosynthetic) Building of complex organic molecules from simpler ones Generally dehydration synthesis Endergonic (consume more energy than produce) ATP ADP + P i + energy Rxn’s all determined by enzymes and coupled together

4. Metabolism: Overview [insert Metabolism_Overview.jpg ] CD: Open with Firefox

5. But reactions happen very SLOWLY by themselves....to make reactions go FASTER we need.........

6. ENZYMES !

7. Enzymes Biological catalysts Each act on a specific substance (substrate) Has active site for substrate to bind to –“loading dock” Each catalyzes only one reaction Sensitive to temperature, pH, concentration Can become denatured All end in -ase

8. Enzymes Large 3-D globular molecule Composed of two parts 1. Protein portion (apoenzyme) –Inactive if alone 2. Nonprotein component (cofactor) –Ions of iron, zinc, magnesium or calcium –If organic = coenzyme Together with the apoenzyme and cofactor = active enzyme (holoenzyme)

9. Enzymes: Steps in a Reaction [insert Enzymes_Steps.jpg ] CD animation: open with Firefox

10. Enzymes: Overview [insert Enzymes_Overview.jpg ] CD animation - open with Firefox

11. HOW DO YOU CONTROL GROWTH OF BACTERIA ??

12. CONTROL THEIR ENZYMES ! (Using inhibitors)

13. Inhibitors Competitive Inhibitors Fill the active site of an enzyme and compete with the normal substrate for the active site Similar shape and chemical structure Does not produce products Example: Sulfa drug Animation: CD

14. Inhibitors Noncompetitive Inhibitors Do not compete with the substrate; instead interact with another part of the enzyme Binds and causes the active site to change its shape, making it nonfunctional Allosteric inhibition “other space” Animation: CD

15. Carbohydrate Catabolism Most microorganisms use carbon as primary energy source Oxidation of glucose 1.Cellular Respiration Glycolysis Krebs cycle Electron Transport Chain 2.Fermentation Glycolysis Products: Alcohol or lactic acid

17. Fermentation Releases energy from sugars or other organic molecules Does not require oxygen Produces only a small amount of ATP

18. Alcohol Fermentation: Saccharomyces (yeast) Heterolactic: produce both Lactic Acid Fermentation Homolactic: only make lactic acid Streptococcus Lactobacillus Bacillus

19. Lipid and Protein Catabolism LIPIDS Produce enzymes called lipases Break down into fatty acid and glycerol Put into the Kreb cycle Also use this to break down petroleum products - oil spills PROTEINS Produce proteases and peptidases Convert proteins into different substance and enter Kreb cycle

20. Photosynthesis

21. Conversion of light energy into chemical energy Chemical energy then used to convert CO 2 into sugars (carbon fixation) Cyanobacteria Animation

22. REVIEW Cellular Respiration –Aerobic –Carbon Fermentation –Anaerobic –Carbon Photosynthesis –Carbon Fixation –Light energy Protein Catabolism –Use Kreb Cycle Lipid Catabolism –Use Kreb Cycle

23. Classifying Bacteria- Nutritional Pattern HOW DO THEY GET ENERGY? Phototrophs: use light as primary energy source Chemotrophs: use reactions of inorganic or organic compounds for energy HOW DO THEY GET CARBON? Autotrophs: CO 2 as principle carbon source Heterotrophs: organic carbon source

24. PHOTOAUTOTROPHS Energy: light Carbon: CO 2 Examples: cyanobacteria Green and Purple Bacteria - use sulfur or hydrogen gas to reduce CO 2 and make organic compounds, not H 2 0 Do not produce O 2 (Anoxygenic) Chromatium - Purple Bacteria Found in sulfide- containing freshwater habitats Chlorobium- Green Bacteria found in hot springs, cold lakes and sediments

25. PHOTOHETEROTROPHS Energy: Light Carbon: organic compounds Anoxygenic Examples: Green nonsulfur bacteria Chloroflexus (found in hot springs, lakes, hyersaline environments) Purple nonsulfur bacteria Rhodopseudomonas (found in soil and marine environments)

26. CHEMOAUTOTROPHS Energy: inorganic compounds Ex: H 2 S, S, NH 3, H 2, CO Carbon: CO 2 -fix CO2 Example: Beggiatoa - use H 2 S, found in soil, sulfur springs, mud layers of lakes, Deep Sea Vents http://www.teachersdomain.org/asset/tdc02_v id_deepseavents/

27. CHEMOHETEROTROPHS Energy: organic compounds Ex: glucose *use the electrons from H-atoms as energy source Carbon: organic compound *Hard to distinguish-use the same compound Example: Streptococcus pneumonia - fermentation

29. http://people.eku.edu/ritchisong/RITCHISO/energyflowchart.jpg http://www.hepafilters.com/images/microbes.jpg http://www.bio12.com/ch6/RemedialEnzymes_file s/image007.jpghttp://www.bio12.com/ch6/RemedialEnzymes_file s/image007.jpg http://classes.midlandstech.edu/carterp/Courses/bi o225/chap05/Slide13.GIFhttp://classes.midlandstech.edu/carterp/Courses/bi o225/chap05/Slide13.GIF