Overview
This lecture covers the process of respiration in living cells, comparing aerobic and anaerobic respiration, their equations, and key similarities and differences.
The Purpose of Respiration
- Respiration is the process that releases energy from food, especially glucose.
- All living cells (plants, animals, and bacteria) carry out respiration to stay alive.
Aerobic Respiration
- Aerobic respiration uses oxygen to release energy from glucose in cells.
- The equation for aerobic respiration: glucose + oxygen → carbon dioxide + water (+ energy released).
- Oxygen and glucose are delivered to cells by the blood; carbon dioxide and water are removed as waste.
- Aerobic respiration releases more energy than anaerobic respiration.
Anaerobic Respiration
- Anaerobic respiration occurs without oxygen when cells can't get oxygen fast enough.
- The equation for anaerobic respiration: glucose → lactic acid (+ less energy released).
- Lactic acid is produced, leading to muscle fatigue during intense exercise.
- Anaerobic respiration releases less energy than aerobic respiration.
Comparison of Aerobic and Anaerobic Respiration
- Aerobic respiration requires oxygen; anaerobic does not use oxygen.
- Aerobic produces carbon dioxide and water; anaerobic produces lactic acid (no carbon dioxide or water).
- Aerobic releases more energy; anaerobic releases less energy.
- Both use glucose and both release energy (never say 'produce energy').
- Only anaerobic respiration results in lactic acid buildup.
Key Terms & Definitions
- Respiration — Process by which cells release energy from food.
- Glucose — A simple sugar that is a key energy source for cells.
- Aerobic Respiration — Respiration using oxygen, producing carbon dioxide and water, and releasing energy.
- Anaerobic Respiration — Respiration without oxygen, producing lactic acid and releasing less energy.
- Lactic Acid — Substance produced in anaerobic respiration causing muscle fatigue.
Action Items / Next Steps
- Download and complete the provided work-along sheet or take thorough notes in your notebook.
- Practice writing both respiration equations from memory.
- Prepare to compare aerobic and anaerobic respiration for future assessments.