Introduction:

• Aerobic respiration is a process by which cells in our body produce energy from food, specifically glucose, in the presence of oxygen.
• It is the most efficient way to generate energy in cells.

Stages of Aerobic Respiration:

1. Glycolysis:
   • Takes place in the cytoplasm.
   • Glucose is broken down into two molecules of pyruvate.
   • A small amount of ATP is generated.
   • NADH is produced as well.
2. Pyruvate Decarboxylation:
   • In the presence of oxygen, pyruvate enters the mitochondria.
   • It is converted to acetyl-CoA, which is a high-energy molecule.
3. Krebs Cycle (Citric Acid Cycle):
   • Occurs in the mitochondria.
   • Acetyl-CoA enters this cycle.
   • Carbon molecules are oxidized, releasing carbon dioxide.
   • NADH and FADH2, carrying high-energy electrons, are produced.
4. Electron Transport Chain (ETC):
   • High-energy electrons from NADH and FADH2 are transferred through a chain of proteins in the inner mitochondrial membrane.
   • This movement of electrons creates a flow of protons (H+).
   • Establishes a proton gradient.
5. ATP Synthesis:
   • Protons flow back into the mitochondria through ATP synthase enzymes.
   • This generates ATP through a process called oxidative phosphorylation.

The overall chemical equation for aerobic respiration is:

C₆H₁₂O₆ (glucose) + 6 O₂ (oxygen) → 6 CO₂ (carbon dioxide) + 6 H₂O (water) + ATP (energy)

Energy Production:

• The complete oxidation of one glucose molecule produces approximately 36-38 molecules of ATP.
• Also generates carbon dioxide and water as waste products.

Importance of Aerobic Respiration:

• Provides the majority of the energy required for our daily activities.
• Essential for sustaining life and ensuring our cells function properly.

Contrast with Anaerobic Respiration:

• Anaerobic respiration occurs in the absence of oxygen.
• It is less efficient in terms of ATP production and can lead to the buildup of lactic acid or ethanol.