Final answer:
The three necessary items for aerobic respiration are glucose, oxygen, and enzymes involved in the Krebs cycle and electron transport chain.
Step-by-step explanation:
The three items necessary for aerobic respiration are glucose (or other nutrients like amino acids and fatty acids), oxygen, and enzymes for the Krebs cycle and the electron transport chain (ETC). Glucose is the primary fuel molecule which, in the presence of oxygen, gets broken down to produce carbon dioxide, water, and ATP (adenosine triphosphate), the energy currency of the cell. Oxygen acts as the final electron acceptor in the ETC, which is crucial for completing the process of energy production.
Without the presence of oxygen, cells will turn to anaerobic processes such as fermentation to generate energy, which is less efficient than aerobic respiration. The Krebs cycle and the ETC are vital components of aerobic respiration and they occur in the mitochondria of the cell, often referred to as the powerhouse of the cell. Enzymes and supporting co-factors like NAD+ and FAD are also critical for the efficient flow of electrons and the generation of ATP during this process.