Lecture Notes: Aerobic Cellular Respiration in Eukaryotic Cells

Introduction to ATP and Cellular Respiration

• ATP (Adenosine Triphosphate)
  • Energy currency used by cells
  • Type of nucleic acid with three phosphates
  • Cells perform processes such as active transport and require ATP

Types of Cells and ATP Production

• Both prokaryotic and eukaryotic cells need to produce ATP
• Eukaryotic Cells
  • Have membrane-bound organelles such as nucleus and mitochondria
  • Found in protists, fungi, animals, and plants
  • Mitochondria play a crucial role in aerobic respiration

Aerobic Cellular Respiration Process

• Overall Goal: Making ATP
• Equation: Reactants (inputs) on the left, products (outputs) on the right
  • Similar to photosynthesis but not opposite
  • Cellular respiration breaks down glucose to make ATP

Steps of Aerobic Cellular Respiration

1. Glycolysis

   • Occurs in the cytoplasm (anaerobic)
   • Converts glucose to pyruvate
   • Net yield: 2 pyruvate, 2 ATP, 2 NADH
   • NADH transfers electrons for ATP production later

2. Intermediate Step

   • Pyruvate transported into mitochondria
   • Pyruvate oxidized to acetyl CoA
   • Produces CO2 and 2 NADH

3. Krebs Cycle (Citric Acid Cycle)

   • Occurs in mitochondrial matrix (aerobic)
   • Acetyl CoA enters the cycle
   • Produces 2 ATP, 6 NADH, 2 FADH2, and releases CO2
   • NADH and FADH2 transfer electrons

4. Electron Transport Chain and Chemiosmosis

   • Occurs in the inner mitochondrial membrane (aerobic)
   • Electrons transferred from NADH and FADH2
   • Generates proton gradient across membrane
   • ATP synthase enzyme converts ADP to ATP
   • Oxygen acts as final electron acceptor forming water
   • Produces 26-34 ATP in this step (varies)

Total ATP Yield

• Range of total ATP from glucose: 30-38 per molecule
• Importance of understanding range rather than exact number

Alternative Process: Fermentation

• Used when oxygen is not available
• Less efficient than aerobic respiration

Importance of ATP Production

• Cyanide can block electron transport chain and ATP production
• Mitochondrial diseases research is ongoing

Conclusion

• Importance of cellular processes and continuous research
• Encouragement to stay curious in scientific learning

These notes cover the essential aspects of aerobic cellular respiration in eukaryotic cells, highlighting the steps involved, importance of ATP, and alternative processes like fermentation.