Lecture Notes: Aerobic Cellular Respiration in Eukaryotic Cells

Introduction

• Mornings and energy comparison with cells
• Cells constantly perform processes like active transport
• Importance of ATP (Adenosine Triphosphate) as the energy currency
  • ATP is a nucleic acid with three phosphates

ATP Production in Cells

• All cells (prokaryote/eukaryote) must make ATP
• Different processes for ATP production depending on cell type

Aerobic Cellular Respiration in Eukaryotic Cells

• Focus on eukaryotic cells with organelles like nucleus and mitochondria
• Includes cells from protists, fungi, animals, and plants
  • Mitochondria play a key role

Equation for Aerobic Cellular Respiration

• Reactants (inputs) on the left, products (outputs) on the right
• Similar to photosynthesis equation but not opposites
  • Glucose produced in photosynthesis is used in respiration

Importance of Glucose

• Germinating seeds use stored glucose for respiration
• Plants can perform both photosynthesis and cellular respiration
• Non-photosynthetic organisms need external glucose sources

Steps of Aerobic Cellular Respiration

Step 1: Glycolysis

• Occurs in the cytoplasm (anaerobic)
• Conversion of glucose to pyruvate
• Net yield: 2 pyruvate, 2 ATP, 2 NADH
  • NADH: a coenzyme transferring electrons
• Pyruvate transported to mitochondria and converted to Acetyl CoA

Step 2: Krebs Cycle (Citric Acid Cycle)

• Occurs in the mitochondrial matrix (aerobic)
• Acetyl CoA enters the cycle
• Release of carbon dioxide and production of 2 ATP, 6 NADH, 2 FADH2
  • FADH2: another electron-transferring coenzyme

Step 3: Electron Transport Chain and Chemiosmosis

• Occurs in the inner mitochondrial membrane (aerobic)
• Electrons transferred to protein complexes and carriers, generating a proton gradient
• ATP synthase enzyme facilitates ATP production
• Final electron acceptor: oxygen (produces water)
• Produces a significant amount of ATP compared to other steps
• ATP yield varies (26-34 ATP per glucose in this step)
• Total yield range: 30-38 ATP per glucose molecule

Alternative ATP Production: Fermentation

• Occurs when oxygen is unavailable
• Less efficient than aerobic respiration

Importance and Implications

• Importance of ATP for cell functions
• Example of cyanide blocking ATP production
• Research on mitochondrial diseases continues to grow

Conclusion

• Encouragement to remain curious about cellular processes

Note: For additional information, check further reading materials and related videos.