question_answer

  Differentiate between rough endoplasmic reticulum (RER) and smooth endoplasmic reticulum (SER). How endoplasmic reticulum is important for membrane biosynthesis?   

Answer:

     

Rough Endoplasmic Reticulum (RER)	Smooth Endoplasmic Reticulum (SER)
In RER, ribosomes are attached to its surface	In SER, ribosomes are not attached to its surface
It helps in protein synthesis	It helps in lipid synthesis
It is formed of tubules and situated near the nucleus.	It is formed of cisternae and situated near the plasma membrane.

Importance of ER in membrane biosynthesis are                                                                 (i) RER synthesise proteins, which are passed to Golgi apparatus. (ii) The SER helps in manufacture of fat and lipids, which along with protein help in building of cell membrane. (iii) Thus, endoplasmic reticulum helps in transporting the proteins to various places. (2)