Final answer:
Cellular respiration is the necessary reaction for a cell to carry on activities after food goes into the mitochondria. This metabolic process converts glucose, proteins, and fats into ATP, the cell's main energy source.
Step-by-step explanation:
In order for a cell to carry on activities after food goes into the mitochondria, the reaction that must occur is known as cellular respiration. Cellular respiration is a series of metabolic reactions that takes place in the cytoplasm and mitochondria of a cell. It involves the conversion of glucose, proteins, and fats into ATP (adenosine triphosphate), which is the cell's main energy-carrying molecule.
During cellular respiration, glucose is broken down into pyruvate in a process called glycolysis. The pyruvate molecules then enter the mitochondria, where they are further oxidized into Acetyl CoA and carbon dioxide via the Krebs cycle. Finally, in the process of oxidative phosphorylation, the energy extracted from food is used to produce ATP through the electron transport chain. Overall, cellular respiration is essential for providing the cell with the energy it needs to carry out its activities after food enters the mitochondria.