3.1. Which athletic event relies the most on anaerobic respiration?
3.2. Explain your answer in QUESTION 3.2.1. above.
3.3. Name two end products of aerobic respiration in muscle cells.
3.4. Explain what you understand by the term 'oxygen debt'?
3.5. Tabulate TWO differences between aerobic and anaerobic respiration.

Aerobic and anaerobic respiration are used to supply energy during exercise. During certain types of exercise, for example, athletics events such as 100m, 200m, 1500m and 3000m, the muscles are unable to obtain sufficient oxygen for the removal of large quantities of lactic acid from their cells. When sprinting, an athlete cannot possibly inhale more than a fraction of the oxygen required, and the body goes into 'oxygen debt'. This debt can only be repaid by rapid breathing after the sprint ends.

3.2. In events like the 100m sprint, athletes exert maximum effort in a short period, usually under 10-15 seconds, which means their muscles require energy quickly. Anaerobic respiration provides this rapid energy without relying on oxygen, as the oxygen supply cannot meet the high demand immediately.

3.3. Two end products of aerobic respiration in muscle cells are carbon dioxide (CO₂) and water (H₂O).

3.4. 'Oxygen debt' refers to the amount of oxygen required to metabolize the accumulated lactic acid produced during anaerobic respiration after intense exercise. When there's insufficient oxygen, like during a sprint, muscles produce energy anaerobically, leading to lactic acid build-up. After exercise, the body needs extra oxygen to convert this lactic acid back into pyruvate and to restore normal metabolic conditions.

3.5.

Characteristic

Aerobic Respiration

Anaerobic Respiration

Oxygen Requirement

Requires oxygenDoes not require oxygen

End Products

Carbon dioxide and waterLactic acid (in muscles) or ethanol and carbon dioxide (in yeast)

This question examines the physiological aspects of respiration during exercise, highlighting the differences between aerobic and anaerobic processes. Understanding these concepts is crucial for explaining how athletes manage energy during varying intensities of physical activity.