Microbial metabolism

• What are the two main types of metabolism?

  Catabolism and anabolism
• What does catabolism provide for anabolism?

  Building blocks and energy
• What is a metabolic pathway?

  Sequence of enzymatically catalyzed reactions
• What determines a metabolic pathway?

  Enzymes
• What encodes enzymes?

  Genes
• What is the collision theory?

  Chemical reactions occur when particles collide
• What is needed for chemical reactions to occur?

  Activation energy
• What are biological catalysts?

  Specific for reactions and not consumed
• What is the turnover number for enzymes?

  1-10,000 molecules per second
• What can denature enzymes?

  Temperature and pH
• What is competitive inhibition?

  Inhibition where substrates compete for active sites
• How does substrate concentration affect enzyme activity?

  Higher concentration increases reaction rate
• What is noncompetitive inhibition?

  Inhibition where substrates do not compete for active sites
• What is feedback inhibition?

  Process where the end product inhibits an enzyme
• What is a redox reaction?

  Oxidation reaction paired with a reduction reaction
• How is ATP generated from redox reactions?

  Energy from electron transfer generates ATP
• What is substrate-level phosphorylation?

  Transfer of high-energy PO4– to ADP
• What is the role of NADH in glycolysis?

  It is produced during the oxidation of glucose
• What happens to pyruvic acid after glycolysis?

  It is oxidized and decarboxylated
• What is the equation for glycolysis?

  Glucose + 2 ATP + 2 ADP + 2 PO4– + 2 NAD+ → 2 pyruvic acid + 4 ATP + 2 NADH + 2H+
• What does the oxidation of acetyl CoA produce?

  NADH and FADH2
• What is the pentose phosphate pathway?

  Uses pentoses and NADPH, operates with glycolysis
• What does the Entner-Doudoroff pathway produce?

  NADPH and ATP
• What is the function of the electron transport chain?

  Passes electrons to produce ATP by chemiosmosis
• What is oxidative phosphorylation?

  ATP generation through electron transport chain
• What is the final electron acceptor in aerobic respiration?

  Molecular oxygen (O2)
• What is anaerobic respiration?

  Final electron acceptor is not O2
• What are the products of alcohol fermentation?

  Ethyl alcohol and CO2
• What does lactic acid fermentation produce?

  Lactic acid
• What is homolactic fermentation?

  Produces lactic acid only
• What is heterolactic fermentation?

  Produces lactic acid and other compounds
• What is the role of extracellular proteases?

  Break down proteins into amino acids
• What is the purpose of metabolic pathways with both catabolic and anabolic functions?

  To efficiently manage energy and resources
• What are the main nutritional types of organisms based on energy and carbon sources?

  • Photoautotroph: Light, CO2
  • Photoheterotroph: Light, Organic compounds
  • Chemoautotroph: Chemical, CO
  • Chemoheterotroph: Chemical, Organic compounds
• What are the biosynthesis pathways mentioned in the study material?

  • Amino acid and protein biosynthesis
  • Lipid biosynthesis
  • Polysaccharide biosynthesis
  • Purine and pyrimidine biosynthesis
• What are the steps of aerobic respiration and their locations in eukaryotes and prokaryotes?

  • Glycolysis: Cytoplasm (both)
  • Intermediate step: Cytoplasm (both)
  • Krebs cycle: Mitochondrial matrix (eukaryotes), Cytoplasm (prokaryotes)
  • Electron transport chain: Mitochondrial inner membrane (eukaryotes), Plasma membrane (prokaryotes)
• What are the products of glycolysis and the Krebs cycle?

  • Glycolysis: 4 ATP, 2 NADH
  • Krebs cycle: 2 ATP, 6 NADH, 2 FADH2
• What are the differences between aerobic and anaerobic respiration?

  • Aerobic: Final electron acceptor is O2
  • Anaerobic: Final electron acceptor is not O2
• What are the fermentation types and their products?

  • Alcohol fermentation: Ethyl alcohol + CO2
  • Lactic acid fermentation: Lactic acid
  • Homolactic: Lactic acid only
  • Heterolactic: Lactic acid + other compounds
• What is the significance of the Calvin-Benson cycle?

  • Fixes CO2 into organic molecules
  • Operates in photoautotrophs