Cellular respiration is the process through which cells convert sugars into energy. It's a fundamental concept in biology. The primary energy currency is ATP. This process involves the Mitochondria, which is known as the powerhouse of the cell.

There are three main stages:
1. Glycolysis
2. The Krebs Cycle (Citric Acid Cycle)
3. Electron Transport Chain

Understanding this is crucial for Biochemistry.