Answer 1

Smooth endoplasmic reticulum (SER):

1. Depending on cell type, it helps in the synthesis of lipids for e.g. Steroid secreting cells of the cortical region of the adrenal gland, testes and ovaries.
2. Smooth endoplasmic reticulum plays a role in detoxification in the liver and storage of calcium ions (muscle cells). 

Rough Endoplasmic Reticulum (RER):

1. Rough ER is primarily involved in protein synthesis. For e.g. Pancreatic cells synthesize the protein insulin in the ER.
2. These proteins are secreted by ribosomes attached to rough ER and are called secretory proteins. These proteins get wrapped in a membrane that buds off from the transitional region of ER. Such membrane-bound proteins depart from ER as transport vesicles.
3. Rough ER is also involved in the formation of membrane for the cell. The ER membrane grows in place by the addition of membrane proteins and phospholipids to its own membrane. Portions of this expanded membrane are transferred to other components of the endomembrane system