Mitochondria

"Mitochondria is the powerhouse of the cell!"
 - Everyone

Mitochondria is an organelle. Its main ability is Cellular Respiration, producing ATP with oxygen and glucose. Mitochondria is useful for any cell, as ATP is always a necessary resource.

Structure
The mitochondria has a double-membrane structure, allowing reactions to be contained while also allowing transport. It can be upgraded to increase its cristae (inner folds), increasing respiration speed.

Cellular Respiration
Cellular Respiration takes place on the inner surface of the inner membrane. Increased cristae count results in more surface area, allowing more reactions to occur.

Synergy
Ribosomes synthesize proteins, allowing the mitochondria to self-replicate.
Stores its own DNA, like the nucleus.