Question

The most important function of endoplasmic reticulum is
A) Protein synthesis
B) Nourishing the nucleus
C) Secretion of materials
D) To give shape to the cell

Answer 1

Hint: Cell organelles are described as specialized structures that are present inside the cell environment and perform specific types of functions. Most of the organelles may or may not be bound by membranes. The membrane bound organelles are various organelles such as ribosomes, endoplasmic reticulum, nucleus, mitochondria etc.

Complete answer:
Cell organelles are present inside the cell and are important in cell functioning. They are responsible for maintaining various types of cells, cell secretion and other biological processes.
The endoplasmic reticulum is present as an important part of the cell structures and is a transport network for the molecules to move to different specific places and is found in most of the eukaryotic cells. It appears as a series of flattened sac-like structures that are found in the cytoplasm of the cell. They form an interconnected network of membrane enclosed sacs known as the cisterna and tubular structures.
The endoplasmic reticulum is composed of two types of units which are known as the rough endoplasmic reticulum and the smooth endoplasmic reticulum. The surface of the rough endoplasmic reticulum contains ribosomes on the surface which gives them a rough appearance while the smooth endoplasmic reticulum does not contain the ribosomes.
 The most important function of the endoplasmic reticulum is the process of synthesis of proteins. The proteins are processed by the ribosomes present on the surfaces of the endoplasmic reticulum. The proteins that are produced are folded and are sent to several parts of the cell which are required for different processes. The proteins are transported by the vesicles further to the Golgi. The endoplasmic reticulum serves as a specific pathway for protein sorting and protein trafficking.
The smooth endoplasmic reticulum lacks the ribosomes but they are involved in the lipid synthesis but they are not involved in the lipid metabolism. The other important functions of the smooth endoplasmic reticulum involve production of steroid hormones and detoxification to help the cell to get rid of toxins produced inside the cell.

Therefore, the correct option is option A.

Note: The endoplasmic reticulum is an important cell organelle that appears as a network of flattened sac like structures. It is primarily associated with the process of protein synthesis and transportation of the processed protein to different parts of the cell through proper delivery channels. It is also responsible for folding and trafficking of proteins.