Cellular respiration - We learned that the mitochondrion is the organelle that breaks down food to produce energy which is stored in a molecule called adenosine triphosphate or ATP. The ATP powers many of the chemical reactions that enable cells to survive. The process of breaking down food to produce ATP is called cellular respiration. We learned that cellular respiration takes place in the cytoplasm and cell membranes of prokaryotic cells. Plants, animals, and most other organisms use cellular respiration to get energy from food.