Lecture 9: Microbial Metabolism

• What are microbial metabolism processes?

  Interconnected biochemical reactions in cells
• What is a metabolic pathway?

  A series of enzyme-catalyzed reactions
• What are the two main types of metabolic pathways?

  1. Catabolic Pathway
  2. Anabolic Pathway
• What do catabolic pathways do?

  Break down complex molecules into simpler ones
• What is released during catabolic pathways?

  Thermal energy stored in chemical bonds
• What is the purpose of glycolysis?

  Convert glucose into pyruvate, producing ATP
• What does the Krebs Cycle produce?

  NADH, FADH₂, ATP, and CO₂
• What is the role of the Electron Transport Chain?

  Produces ATP by transferring electrons
• What does beta-oxidation do?

  Breaks down fatty acids into acetyl-CoA
• What is protein catabolism?

  Degrades proteins into amino acids for energy
• What do anabolic pathways involve?

  Synthesis of complex molecules from simpler ones
• Where does the energy for anabolic pathways come from?

  ATP generated during catabolic processes
• What is fermentation?

  • Anaerobic process
  • Converts sugars into acids, gases, or alcohol
  • Allows ATP production without oxygen
• What is metabolic regulation?

  Mechanisms controlling the rate of metabolic pathways
• What is feedback inhibition?

  End product inhibits an earlier step in a pathway
• What is allosteric regulation?

  Molecules bind to enzymes to alter activity
• What is autotrophic metabolism?

  • Organisms use inorganic substances as carbon source
  • Use light or chemical energy for metabolic processes
• What is photosynthesis?

  Converts light energy into chemical energy
• What is chemosynthesis?

  Converts inorganic molecules into organic molecules
• What is heterotrophic metabolism?

  • Organisms obtain energy from organic compounds
  • Rely on consuming other organisms or organic matter
• What is respiration?

  Includes aerobic and anaerobic processes
• What are the types of metabolic regulation mechanisms?

  1. Feedback inhibition
  2. Allosteric regulation
• What is amphibolic regulation?

  • Functions both catabolically and anabolically
  • Important pathways: glycolytic pathway and TCA cycle
• What are the types of energy-generating metabolism?

  1. Aerobic respiration
  2. Anaerobic respiration
  3. Fermentation
• What is aerobic respiration?

  Converts biochemical energy into ATP using oxygen
• What is anaerobic respiration?

  Occurs without oxygen, using other molecules
• What are various prokaryotic energy production processes?

  1. Fermentation
  2. Anaerobic respiration
  3. Aerobic respiration
  4. Lithotrophy
  5. Photoheterotrophy
  6. Anoxygenic photosynthesis
  7. Methanogenesis
• What are enzymes?

  Protein catalysts that speed up reactions
• What is a catalyst?

  Substance increasing reaction rate without alteration
• What are substrates?

  Reacting molecules in a chemical reaction
• What are products?

  Substances formed from a chemical reaction
• What are the characteristics of enzymes?

  • Active site
  • Specificity
  • Modified forms: inactive, active
• What is the function of coenzymes and cofactors?

  Assist enzymes in catalyzing reactions
• How are enzymes named?

  By adding “-ase” to the substrate
• What is lipase?

  An enzyme that breaks down lipids
• What is DNase?

  An enzyme that breaks down DNA
• What is protease?

  An enzyme that breaks down proteins
• What does dehydrogenase do?

  Removes a hydrogen from a molecule
• What does phosphatase do?

  Removes a phosphate group from a molecule
• What are the groups of enzymes based on their reactions?

  1. Oxidoreductases – oxidation & reduction
  2. Hydrolases – hydrolysis