Ribosomes are found in cytoplasm and on rough ER, they're very small. They produce proteins using instructions from DNA.
The endoplasmic reticulum is a transportation system with a series of tunnels through cytoplasm. The rough endoplasmic has ribosomes on the surface and inside it detoxifies drugs and manufactures lipids.. The smooth endoplasmic has proteins altering inside.
The Golgi Apparatus is a series of tubes found throughout the cell, where is package proteins.
The mitochondria is an oval shaped capsule of membranes. Its the power plant of the cell and it converts the chemical energy stored in food into ATP (energy usable by cells).