Lecture Notes: Electron Transport System and Fermentation

Fermentation in Bacteria

• Heterofermentative Organisms:
  • Can produce more than one product from fermentation.
• Homofermentative Organisms:
  • Produce only one product from fermentation.
• Fermentation Products:
  • Wide variety, some with unpleasant odors (e.g., butyric acid).
  • Example products:
    • Acetone (found in nail polish remover).
    • Isopropyl alcohol (used as an antiseptic).

Importance of Glycolysis, Krebs Cycle, and Electron Transport Chain

• Central to metabolism in cells.
• Shown as catabolic pathways but can also reverse (anabolism).
• Key Processes:
  • Glucose → Pyruvate → Amino acids.
  • Acetyl CoA and Krebs Cycle intermediates convert to amino acids.
  • Glyceraldehyde 3-phosphate converts to glycerol for lipid synthesis.
  • Acetyl CoA critical for fatty acid synthesis.

Breakdown of Fats

• Efficient method for energy production.
• Process:
  • Triglycerides break into glycerol and fatty acids.
  • Undergo beta-oxidation.
  • Acetyl CoA enters Krebs Cycle, producing ATP.

Biochemical Pathways in Cells

• Complexity of cellular biochemistry.
• Central Pathways:
  • Glycolysis and Krebs Cycle at the core.
  • Electron Transport Chain components in the lipid bilayer.
• Interconnection between pathways:
  • Some pathways independent, many linked through intermediates.

Conclusion

• Appreciation for the complexity of cellular biochemistry.
• Next step: Review and prepare for the exam.