| Rough endoplasmic reticulum | Smooth endoplasmic reticulum | |
| 1. | They have ribosomes attached on their surfaces. | They do not have ribosomes attached on their surfaces. |
| 2. | RER manufactures proteins and transports them to various places. | SER helps in manufacturing lipids and transports them to various places. |
Endoplasmic reticulum act as main site for synthesis of protein and lipids which are needed for the biogenesis of plasma membrane.