The endoplasmic retculum, also known as the ER, has many characteristics such as the proteins for use in the cell are made by the ribosomes that are free in the cytoplasm, there are 2 ER's there is the rough and the smooth one. The rough ER has ribosomes attached to it, it also manufactures proteins. The Smooth ER has enzymes that make fats, phospolipids, ans steroids. Together the ER transports substances around the cell.
