1. Respiration By the end of this lesson, I will be able to: Understand what respiration is Know the difference between aerobic and anaerobic respiration Know what oxygen debt is in relation to exercise.

2. Respiration What is respiration? -Respiration is the release of energy from food which takes place in the living cells. In muscle fibres and other body cells, energy is obtained from glucose.

3. Aerobic Respiration RequiresProduces Glucose Carbon dioxide + water + energy Oxygen Here, 1 mole of glucose = 2830 kj of energy. Supplies energy for long periods of time. However, it takes 90 seconds after starting exercise before the aerobic system will work.

4. Anaerobic Respiration Because oxygen does not reach the muscles fast enough, we use the anaerobic system. RequiresProduces Glucoseenergy + lactic acid Here, 1 mole of glucose = 118 kj of energy. The same amount of glucose will produce less energy but produced much faster.

5. Oxygen debt After 60-90 seconds, lactic acid makes muscles tired and painful. This creates an oxygen debt. Muscles need extra oxygen to get rid of lactic acid. Oxygen debt is the amount of oxygen needed to get the body back to its resting state.

6. Check your knowledge!! Answer the following questions: 1.Where do our muscles get energy from? 2.What are the advantages and disadvantages of aerobic respiration? 3.What are the advantages and disadvantages of anaerobic respiration? 4.Name two ways in which you can create an oxygen debt.