Lesson-4_Aerobic-and-Anaerobic-Respiration

Aerobic and Anaerobic Respiration

Introduction to Cellular Respiration

• Involves oxidation and reduction of molecules to produce ATP.

• Primarily uses glucose to generate 30-32 ATP molecules.

Two Categories of Cellular Respiration

• Aerobic Respiration

• Anaerobic Respiration

Aerobic Respiration

• Uses oxygen to produce ATP.

• Stages involved:

  • Glycolysis

  • Krebs Cycle

  • Electron Transport Chain (ETC)

• Occurs mainly in the mitochondria, with glycolysis occurring in the cytoplasm.

Anaerobic Respiration

• Produces ATP without utilizing oxygen.

• Found in bacteria and archaea in low-oxygen environments.

• Utilizes ETC but uses inorganic substances as final electron acceptors.

• Produces less energy per glucose compared to aerobic respiration.

Fermentation

• Does not require oxygen or ETC for ATP production.

Classifications of Fermentation

• Lactic Acid Fermentation

  • Splits glucose into lactic acid producing 2 ATP.

  • Temporary response during intense exercise; occurs in the cytoplasm.

• Alcoholic Fermentation

  • Produces ethanol and NAD+, allowing glycolysis to continue.

  • Explains the rising of bread dough; occurs in the cytoplasm.

Anaerobes

• Obligate Anaerobes: Can only perform anaerobic respiration or fermentation.

• Facultative Anaerobes: Can switch between aerobic respiration and fermentation; thrive in both oxygen-rich and poor environments.

Examples of Anaerobes

• Obligate Anaerobes: e.g., Peptostreptococcus found in human gut; oxygen is toxic.

• Facultative Anaerobes: e.g., Escherichia coli (E. coli) found in intestines; adaptable to conditions.

Similarities of Aerobic and Anaerobic Respiration

• Both undergo glycolysis, converting glucose into pyruvate while producing ATP.

• Both utilize NAD+ as an oxidizing agent, becoming NADH.

Differences Between Aerobic and Anaerobic Respiration