What is the process through which living organisms produce energy called?

The process through which living organisms produce energy is called cellular respiration. This process involves the breakdown of glucose molecules to release energy in the form of ATP (adenosine triphosphate). Cellular respiration occurs in the mitochondria of cells and can be summarized by the following equation:

C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + Energy (ATP)

There are three main stages of cellular respiration:

1. Glycolysis: This is the first stage, where glucose is broken down into two molecules of pyruvate. This process occurs in the cytoplasm and produces a small amount of ATP.
2. Krebs Cycle (Citric Acid Cycle): The pyruvate molecules enter the mitochondria and are further broken down in the Krebs Cycle. This stage produces more ATP and also generates high-energy electrons carried by NADH and FADH₂.
3. Electron Transport Chain (ETC): The final stage takes place in the inner mitochondrial membrane. Here, the high-energy electrons from NADH and FADH₂ are used to produce a large amount of ATP through oxidative phosphorylation.

Cellular respiration is essential for the survival of living organisms as it provides the energy needed for various cellular activities, including growth, repair, and reproduction.