Mitochondrion and Generator
The generator in an airport can be compared to the mitochondrion in a cell.
Mitochondrion in a cell
Generator in an airport
Another name for the mitochondrion is the "power plant." This is because they make energy available to the cell. They provide energy for a cell so it can move, divide, contract etc. Active cells, for example muscle cells, contain more mitochondria while less active cells, for example fat storage cells, contain less mitochondria.
The "power plant" of the airport is a generator. Like the mitochondrion, the generator provides the airport with energy. Just like mitochondria provide energy for the cell to move, divide and contract, a generator supplies power (electricity) for the airport to support critical systems in the airport. These systems include lighting, sewage treatment, baggage conveyors, security systems, terminal information monitors etc. Active cells require more mitochondria than less active cells. Similarly, larger airports with more systems to support, have larger power supplies. Just like active cells, they require more energy, therefore a greater power supply.





Inside a mitochondrion
So, in many ways, the mitochondria of a cell is like the generator of an airport.