the NYC mass transit
The mitochondria would most closely resemble a power plant for a city as the mitochondria is where the energy for a cell is created.
Power House
If a mitochondria was had a job in the city, it'd be a power generator.
A Garbage Incinerator
It is easier to explain the functions of a cell if I explain the parts of it like they were parts of a city. The mitochondria would be the power plant of a city. It is also the power plant of the cell. The mitochondria coverts food that enters the cell into a form that the cell can use.
beans
Recycling center
Power plant
the air ground and space
fpruduction halls
A highway/road :)
There are many things in the world that would represent cytoplasm. In the city the cytoplasm could be represented as the ground where everything is built.