What is the role of mitochondria?

Answer: It powers various functions of the cell and the organism as a whole, just like batteries.

Answer: The most prominent roles of mitochondria are to produce the energy currency of the cell, ATP (i. e., phosphorylation of ADP), through respiration, and to regulate cellular metabolism. The central set of reactions involved in ATP production are collectively known as the citric acid cycle, or the Krebs cycle.