The correct answer is option 'D' - Aerobic respiration.

Explanation:

Aerobic respiration is a process that occurs in the presence of oxygen and involves the breakdown of glucose to produce energy (ATP) for cellular activities. It is the most efficient way of extracting energy from glucose.

Process of Aerobic Respiration:

1. Glycolysis: The first step of aerobic respiration is glycolysis, which takes place in the cytoplasm of the cell. In this step, a molecule of glucose is broken down into two molecules of pyruvate. This process generates a small amount of ATP and NADH.

2. Krebs Cycle (Citric Acid Cycle): The pyruvate molecules produced in glycolysis enter the mitochondria and undergo further breakdown in the Krebs cycle. During this cycle, carbon dioxide is released, and high-energy molecules such as NADH and FADH2 are produced.

3. Electron Transport Chain (ETC): The NADH and FADH2 generated in the Krebs cycle carry high-energy electrons to the electron transport chain, which is located in the inner mitochondrial membrane. Here, the electrons pass through a series of protein complexes, releasing energy. This energy is used to pump protons (H+) across the membrane, creating an electrochemical gradient.

4. Oxidative Phosphorylation: The electrochemical gradient created by the electron transport chain drives the synthesis of ATP through a process called oxidative phosphorylation. ATP synthase, located in the inner mitochondrial membrane, uses the flow of protons to convert ADP (adenosine diphosphate) to ATP (adenosine triphosphate), which is the energy currency of the cell.

5. Final Products: The end products of aerobic respiration are carbon dioxide, water, and a large amount of ATP.

Comparison with Anaerobic Respiration:

Anaerobic respiration occurs in the absence of oxygen and is less efficient than aerobic respiration. It involves the breakdown of glucose, but the final electron acceptor is an inorganic molecule other than oxygen, such as sulfate or nitrate. The end products of anaerobic respiration vary depending on the specific electron acceptor used.

In summary, when the breakdown of glucose occurs with the use of oxygen, it is called aerobic respiration. It is a multi-step process that efficiently produces energy in the form of ATP.