What is the function of mitochondria in cells?

• A. They store genetic information.
• B. They produce ATP, the cell’s energy currency.
• C. They synthesize proteins.
• D. They break down waste products.

Answer: (B)

Mitochondria generate ATP, the cell’s energy currency, through cellular respiration. In this process, glucose and other nutrients are broken down, and the energy released is used to drive the synthesis of ATP from ADP. The inner membrane’s folds, called cristae, increase surface area for the electron transport chain and ATP synthase to produce a large amount of ATP. Oxygen acts as the final electron acceptor, forming water in the process. This ATP provides the energy for activities such as active transport, muscle contraction, and biochemical reactions throughout the cell.

You’ll often hear mitochondria described as the powerhouses of the cell because their main job is to supply usable energy. Other organelles handle different jobs: the nucleus stores genetic information, ribosomes build proteins, and lysosomes break down waste.