Microbial Physiology and Metabolism I — DU B. Sc. (Hons) Microbiology Previous Year Question Papers

1. (a) Classify bacteria based on their nutritional strategies for obtaining energy, carbon and electrons. Illustrate with relevant examples. 8 (b) Provide an example of each of the following (any five) : 5 (i) Antiport system (ii) Electron transport inhibitor (0) Mixotrophic bacterium (vi) Aerotolerant anaerobe. (c) Comment on the significance of ED pathway and list its key enzymes. 3+2=5 2. (a) Write short notes on (any three) : 3×5=15 (ii) Secondary active transport Glyoxylate cycle (b) Give the contributions of the following scientists : 2x1.5=3 3. (a) Draw a diagram showing the organization and sequence of components in the mitochondrial electron transport chain (ETC). Explain the flow of electrons and proton pumping. How does the bacterial ETC differ from the mitochondrial ETC? 6+2+4=12 (b) Expand the following and write their significance (any three) : 3×2=6 4. (a) Differentiate between the following : 3x5=15 (i) Diauxie and Synchronous growth (ii) EMP pathway and Pentose Phosphate Pathway (iii) Electrogenic and electroneutral transport processes (b) Mention the assumptions which formed the basis of chemiosmotic hypothesis. 3 5. (a) Explain why strict anaerobic microorganisms cannot survive in the presence of oxygen. 6 (b) What are compatible solutes ? Give examples and describe the mechanisms by which they help microorganisms adapt to osmotic stress. 2+4=6 (e) Write balanced equations for the reactions catalyzed by the following enzymes (any three) : 3×2-6 (i) Pyruvate kinase Isocitrate dehydrogenase 6. (a) Define the following terms (any four) : Substrate level phosphorylation, Right-side-out vesicle, Batch culture, Balanced growth, Specific growth rate 4x2.5=10 (b) Explain the mechanism/s by which bacteria acquire iron in low-iron environments. 5 (c) List any three adaptations of Psychrophiles. 3