The mitochondria does?

Mitochondria does the following roles:

Production of energy:

The mitochondria is responsible for producing energy that the cell needs. It undergoes a process called oxidative phosphorylation where the chemical energy from the consumed food is converted into the form required by the cellular processes

Calcium storage:

Mitochondria is also responsible for storing calcium needed for the body. It stores calcium ions which are vital in fertilisation, muscle function and blood clotting.

Cell Death:

Mitochondria plays a vital role in a process called apoptosis by releasing the cytochrome C which is responsible destroying cells. It is also responsible for deciding which cells are to be destroyed.

Heat Production:

Mitochondria produces heat through proton leak process which is called as shivering thermogenesis.

The mitochondria is the powerhouse of the cell and creates energy for the cell.