Cellular respiration involves the breakdown of glucose to produce energy in the form of ATP. Glucose undergoes glycolysis, producing pyruvate, which then enters the mitochondria. Through the transition reaction and citric acid cycle, electrons are transferred to NADH and FADH2. These electrons are then used in the electron transport chain to produce ATP through oxidative phosphorylation. Fermentation allows glycolysis to continue under anaerobic conditions by regenerating NAD+ without using oxygen.

4. Glucose Breakdown: Summary Reaction

6. NAD + Cycle

8. Glucose Breakdown: Overview of 4 Phases

10. Glycolysis: The Balance Sheet

11. Substrate-level Phosphorylation

12. Glycolysis

13. Glycolysis

15. Mitochondrion: Structure & Function

16. Preparatory Reaction

18. The Citric Acid Cycle

19. Citric Acid Cycle: Balance Sheet

22. Electron Transport Chain

23. Organization of Cristae

25. Overall Energy Yielded per Glucose Molecule

27. Fermentation

29. Products of Fermentation

30. Efficiency of Fermentation InLine Figure 143

32. The Metabolic Pool Concept