How does rough endoplasmic reticulum differ from smooth endoplasmic reticulum?

2 Answers
Aug 22, 2016

The two differ in their function, and one is smooth and the other is rough.


The smooth endoplasmic reticulum (SER) is smooth, and the rough endoplasmic reticulum (RER) is rough.

Both the SER and RER are large continuous sheets of membrane that fold back on themselves to form an enclosed space (lumen). Think of this as like a cloth bag that has had its opening stitched closed and then the bag screwed-up to make a small ball (see below).

When viewed under an electron microscope (as shown in the image below) the RER looks rough as the surface is coated with ribosomes. The black dots, the ribosomes, are in the cytoplasm of the cell.

Electron micrograph section of Rough Endoplasmic - ref 1.

However, the SER looks smooth, as it does not have ribosomes coating the outside.

Electron micrograph section of Smooth Endoplasmic - ref 2.

The above images are sections. It is as if we have cut through the screwed-up bag mentioned above and are looking at the ends of the folds, but really this is still one bag.

The SER and the RER have different functions. The RER is involved in the production of proteins in the cell, whereas the SER may be involved in the storage of ions, in detoxification, or in the production of lipids.


  1. Image source -
  2. Image source - organelles2011

Smooth and Rough Endoplasmic Reticulums mainly differ on the basis of presenc or absence of ribosomes.


The endoplasmic reticulum is also known as cytoplasmic vascular system. First of all, the name endoplasmic reticulum was coined by K. R. Porter (1948).

The strands of the endoplasmic reticulum are tubes and vesicles. It joins nuclear and cell membrane. The double membranous hollow endoplasmic reticulum contains ribosomes on the upper surface. The Endoplasmic Reticulums are divided into the following two types on the basis of either ribosomes are present or absent.

  1. Rough Endoplasmic Reticulum (RER)-The RER are well-develped in the cells engaged in the protein synthesis. The RER are confined into the basophilic regions of the cells. The ribosomes make the rough appearance. The RERs are sites of protein synthesis.

2.Smooth Endoplasmic Reticulum (SER)-The SER has different smooth morphology compared to the RER. It lacks ribosomes and surface looks smooth. So, it is called as SER. The SERs are concentrated in the glycogen regions of the cells and attached to the perioxosomes and Golgi Complex.
Thank You.
Dr B K Mishra., India.