1. Oxygen is utilised for the breakdown of respiratory substrate. 2. It takes place in cytoplasm (glycolysis) and inside mitochondria (Krebs cycle) 3. End products are carbon dioxide and water 4. More energy is released. | 1. Oxygen is not required. 2. It takes place in cytoplasm only. 3. End products are lactic acid or ethanol and carbon dioxide. 4. Less energy is released. |