Cellular Respiration and Fermentation Lecture Notes

1. Introduction to Metabolic Processes

• Metabolism involves:
  • Anabolism: Requires energy, e.g., protein formation.
  • Catabolism: Releases energy.
• Energy is essential for anabolic processes.

2. Production of Energy

2.1. Main Substrate

• Glucose is the primary substrate for cellular respiration.
• In humans/animals: Obtained from carbohydrate digestion.
• In plants: Produced via photosynthesis using light energy.

2.2. Cellular Respiration Types

• Aerobic Respiration: Requires oxygen.
• Anaerobic Respiration: Does not require oxygen.
• Fermentation: Alternate pathway, occurs without oxygen.

3. Aerobic Respiration

3.1. Overview

• Breaks down glucose using oxygen to produce energy.
• Stages:
  • Glycolysis: Glucose breaks into pyruvate in cytoplasm.
  • Oxidation of Pyruvate: Occurs in mitochondria, producing CO2, water, and energy.

3.2. Word Equation

• Glucose + Oxygen → Carbon Dioxide + Water + Energy (ATP)

3.3. Experiment of Aerobic Respiration

• Investigate using a respirometer to measure oxygen consumption.

4. Fermentation

4.1. Overview

• Incomplete breakdown of glucose without oxygen.
• Types include:
  • Alcohol Fermentation: Produces ethanol and CO2.
  • Lactic Acid Fermentation: Produces lactic acid.

4.2. Experiment in Yeast Fermentation

• Setup involving yeast, glucose, and observing changes in lime water.

4.3. Applications

• Food Production: Beer, wine (alcohol fermentation), yoghurt (lactic acid fermentation).
• Biological Adaptation: Paddy plants perform alcohol fermentation in low oxygen areas.

5. Comparison of Aerobic Respiration and Fermentation

5.1. Similarities

• Both produce ATP and start with glycolysis.

5.2. Differences

• Aerobic Respiration: Complete glucose oxidation, produces water, high energy yield.
• Fermentation: Incomplete oxidation, no water production, lower energy yield.

6. Practical Implications

• Muscle Exercise: Lactic acid accumulation leads to cramps.
• Athletic Training: Increases mitochondria in muscle cells, enhancing aerobic capacity.

7. Summary

• Energy is vital for metabolic processes.
• Glucose is the main substrate for cellular energy production.
• Understanding respiration processes is key to biological and practical applications.