Here's a breakdown:

* Cellular respiration is a series of metabolic reactions that occur in the cells of organisms to convert chemical energy from nutrient molecules (like glucose) into adenosine triphosphate (ATP), which is the primary energy currency of cells.

* This process involves several steps:

* Glycolysis: The initial breakdown of glucose in the cytoplasm.

* Krebs cycle (citric acid cycle): Further breakdown of glucose molecules in the mitochondria.

* Electron transport chain: Production of ATP by transferring electrons down a chain of molecules.

So, the answer is cellular respiration.