MICRO-s10_12 - 3/3/2010 BIOL 240: General Microbiology...

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Unformatted text preview: 3/3/2010 BIOL 240: General Microbiology Spring 2010 Rm. 22-116 R, Mar. 4, 2010 22http://www.smccd.edu/accounts/staplesn/biol240/ 1. Pre-Lab Writeups: Be sure to prepare before each Lab Writeups Be sure to prepare before each Monday’s Monday’s labs (for BOTH Mon. & Wed.)!! – (What? Why? How? are we doing in the lab??) 2. Be sure to keep up with BY ARRANGEMENT HOURS!! They are REQUIRED for your grade!! • -- average TWO documented hours/week. 3. MT1 M/C Answer KEY is posted. Check and MT1 M/C Answer KEY is posted Check and report report any corrections by NEXT TUES! • under “Add’l Materials” tab. “Add’l 4. Lab Quiz #3 due TONIGHT!! sample for group TUE! 5. Bring DRY SOIL sample for your group of 6 TUE! 1. 1. Diagram how high energy electrons are used to produce ATP in the electrons mitochondrial mitochondrial inner membrane (or bacterial plasma mem.). 2. Compare and contrast the energy inputs and outputs of Fermentation & energy Aerobic Respiration/Oxidative phosphorylation. phosphorylation. REVIEW: TODAY’s Objectives: Students should be able to... Students to... 1. Compare transport and final electron acceptors between aerobic aerobic and two different types of anaerobic respiration. respiration. 2. Explain how lipids and proteins are catabolized and energy lipids harvested thru pathways shared with glucose metabolism. 3. Explain how light energy is harvested and stored in the Explain how light energy is harvested and stored in the form form of chemical energy by photosynthetic organisms. organisms. 4. Diagram how catabolic and anabolic pathways can share catabolic intermediates to efficiently regulate energy storage, energy usage, and biosynthesis. 5. ** Distinguish the carbon and energy sources for all of the carbon for trophisms chemo, trophisms: chemo, photo, hetero, auto, and comb’ns of each. and 1 3/3/2010 B. Anaerobic respiration Electron acceptor NO3– SO4– CO32 – Products NO2– ; N2 + H2O H2S + H2O CH4 + H2O 5.7) Fermentation 1. 2. 3. 4. Releases energy from oxidation of organic molecules Does not require oxygen Does not use the Krebs c cle or ETC cycle Uses an organic molecule as the final electron acceptor Figure 5.18b 2 3/3/2010 A. Types of Fermentation • Alcohol fermentation - Produces ethyl alcohol + CO 2 CO • Lactic acid fermentation - Produces lactic acid. – Homolactic fermentation - Produces lactic acid only. – Heterolactic fermentation - Produces lactic acid and other compounds (eg: acetoin). Fermentation Figure 5.23 The Glucose song!!!.... http://www.sciencehttp://www.science-groove.org/Now/Glucose.html Figure 5.19 3 3/3/2010 5.8) Catabolism: A. A. Lipid Catabolism http://www.wiley.com/college/prat t/0471393878/student/animations /citric_acid_cycle/index.html Figure 5.20 B. Protein Catabolism Protein Extracellular proteases Amino acids Organic acid Krebs cycle acid), Deamination ( acid), decarboxylation ( amine), dehydrogenation am Decarboxylation H + CO2 Figure 5.22 http://www.wiley.com/legacy/college/boyer/0470003790/animations/tca/tca.htm 4 3/3/2010 ** Biochemical tests ** • Used to identify bacteria. Dichotomous Key: Key: Figure 10.8 5.9) Photosynthesis • Photo: Conversion of light energy into chemical energy (ATP) – Light-dependent (light) reactions Light- • Synthesis: Fixing carbon into organic molecules – Light-independent (dark) reaction, Calvin-Benson cycle LightCalvinOxygenic: 6 CO2 + 12 H2O + Light energy → C6H12O6 + 6 O2 + 6 H2O Anoxygenic Anoxygenic: CO2 + 2 H2S + Light energy → [CH2O] + 2 A + H2O 5 3/3/2010 A. Cyclic Photophosphorylation ATP ONLY!!!! (No NADPH) B. Noncyclic Photophosphorylation ATP AND NADPH made!!!! NADP PSII “Z“Z-Scheme” of electron Transport: LightLightenergized TWICE!! PSI Fdx Chl Figure 5.25 Noncyclic Pathway “Z“Z-Scheme” of electron Transport: Light-energized TWICE!! Lightsunlight stroma ATP + Pi ATP ATP synthase H+ H+ H+ H+ O H+ H+ H+ photolysis H2O e- ethylakoid membrane NADPH eH+ photosystem II photosystem I NADP+ http://vcell.ndsu.nodak.edu/animations/photosynthesis/movie.htm http://www.fw.vt.edu/dendro/forestbiology/photosynthesis.swf http://www.stolaf.edu/people/giannini/flashanimat/metabolism/photosynthesis.swf 6 3/3/2010 Carbon CarbonFixation! • SYNTHESIS!!! “Dark Reactions” • Using ATP & NADPH made in the light reactions!! CalvinCalvinBenson Cycle: Figure 5.26 5C RuBP Unstable 6C intermediate (15 Carbons) 2x 3C 2x 3C C-fixation!! (15 Carbons) Step-ByStep-By-Step Narration: http://www.cells.de/cellseng/1medienarchiv/Zellfu nktionen/Memb_Vorg/Photosynthese/Dunkel_u_S taerke/Calvin-Bensontaerke/Calvin-Benson-Zyklus/index.jsp 6C + Products **http://www.science.smith.edu/departments/ **http://www.science.smith.edu/departments/ Biology/Bio111/calvin.html Table 5.6 ** Study figure 5. 28!! ** http://www.science.smith.edu/departments/Biology/Bio111/calvin.html http://www.cells.de/cellseng/1medienarchiv/Zellfunktionen/Memb_Vorg/Photosynthese/Dunkel_u_Staerke/Calvin-Benson-Zyklus/index.jsp 7 3/3/2010 • Halobacterium uses bacteriorhodopsin bacteriorhodopsin, – not chlorophyll, – to generate electrons for a chemiosmotic proton pump. 5.10) Chemotrophs • Use energy from chemicals. – Chemoheterotroph Chemohetero Glucose NAD+ ETC Pyruvic acid acid NADH ADP + P ATP • Energy is used in anabolism. 8 3/3/2010 Chemotrophs • Use energy from chemicals. Thiobacillus – Chemoautotroph, Thiobacillus ferroxidans 2Fe2+ NAD+ ETC 2Fe3+ 2 H+ NADH ADP + P ATP • Energy used in the Calvin-Benson cycle to fix CO2. Calvin- 5.11) Phototrophs • Use light energy. Chlorophyll ETC Chlorophyll oxidized ADP + P ATP • Photoautotrophs use energy use energy in in the Calvin-Benson cycle Calvinto fix CO2. • Photoheterotrophs use energy. Figure 5.27 9 3/3/2010 Metabolic Diversity Among Organisms Nutritional type Photoautotroph Energy source Light Carbon source CO2 Example Oxygenic: Cyanobacteria plants. Anoxygenic: Green, purple bacteria. Photohetero Photoheterotroph Chemoautotroph Light Organic Green, purple compounds nonsulfur bacteria. Iron-oxidizing bacteria. bacteria Chemical CO2 Fermentative bacteria. Chemoheterotroph Chemical Organic compounds Animals, protozoa, fungi, bacteria. ** Study figure 5.28!! ** 5.12) Anabolism: Metabolic Pathways of Energy Use A. Polysaccharide Biosynthesis Biosynthesis B. Lipid Biosynthesis Figure 5.29 Figure 5.30 10 3/3/2010 Anabolism/Biosynthesis C. Amino Acid and Protein Biosynthesis Figure 31 Anabolism D. Purine and Pyrimidine Biosynthesis Figure 5.32 11 3/3/2010 5.13) Amphibolic pathways • Are metabolic pathways that have both both catabolic catabolic and anabolic anabolic functions. Figure Figure 5.33 Chapter 6 Microbial Growth Growth 12 3/3/2010 Microbial Growth • Microbial growth = increase in number of cells, not cell size 6.1) Requirements for Growth: Physical Requirements A. Temperature: (Psychro-, meso-, thermo-philes) Psychro- meso- thermo-philes) – – – Minimum growth temperature growth temperature Optimum growth temperature Maximum growth temperature Figure 6.1 13 3/3/2010 The Requirements for Growth: Physical Requirements B. pH: (acido-, neutero-, alkalo-philes) acido- neutero- alkalo-philes) – Most bacteria grow between pH 6.5 & 7.5. – Molds and yeasts grow between pH 5 & 6. – Acidophiles grow in acidic environments. Figure 6.4 C. Osmotic Pressure: – Hypertonic environments -- increase salt or sugar cause plasmolysis. cause plasmolysis. – Extreme or obligate halophiles require high osmotic pressure. halophiles – Facultative halophiles tolerate high osmotic pressure . 6.2) Requirements for Growth: Chemical Requirements 1. Carbon – Structural organic molecules energy source molecules, energy source – Chemoheterotrophs use organic carbon sources – Autotrophs use CO2 3. Sulfur – In amino acids, thiamine, biotin biotin – Most bacteria decompose proteins – Some bacteria use SO42− or H2S 2. Nitrogen 4. Phosphorus – In DNA, RNA, ATP, and membranes – In amino acids, proteins – PO43− is a source of – Most bacteria decompose phosphorus phosphorus proteins 5. Trace Elements – Some bacteria use NH4+ – Inorganic elements -- in or NO3− small amounts – A few bacteria use N2 in – Usually as enzyme nitrogen fixation cofactors 14 3/3/2010 The Requirements for Growth: Chemical Requirements • Oxygen (O2) (Eg: BHIA deep agar tubes) Toxic Forms of Oxygen 1. Singlet oxygen: O2 boosted to a higher-energy higherstate 2. Superoxide free radicals: O2− • • uuuuuuuuuuuuuur O2 − + O2 − + 2H + superoxide dismutase H2O2 + O2 3. Peroxide anion: O22− H+ 4. Hydroxyl radical (• OH) 15 3/3/2010 6.3) Culture Media • Chemically Defined Media: Exact chemical composition is known composition is known – “minimal media” – many additives for “fastidious” species “fastidious” • Complex Media: Extracts and digests of Media Extracts and digests of yeasts, yeasts, meat, or plants – Nutrient broth – Nutrient agar A. Selective Media • Suppress unwanted microbes and encourage desired encourage desired microbes. microbes. – EMB – MacConkey – NaCl-Mannitol NaCl– Min. Glc/Nitrate Glc/Nitrate Figure 6.10 16 ...
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