Endoplasmic Reticulum – Types and Functions

Endoplasmic reticulum is a network of tubular and microsomal vesicular structures which are adjoined with one another. It is covered by a restricting membrane which is formed by proteins and bilayered lipids. The lumen of endoplasmic reticulum consists of a fluid medium called endoplasmic matrix. The size of the lumen has to do with 400 to 700 Å. The endoplasmic reticulum forms the link in between nucleus and cell membrane by linking the cell membrane with the nuclear membrane.

Types of Endoplasmic Reticulum

Endoplasmic reticulum is of 2 types, specifically rough endoplasmic reticulum and smooth endoplasmic reticulum. Both the types are adjoined and constant with one another. Relying on the activities of the cells, the rough endoplasmic reticulum modifications to smooth endoplasmic reticulum and vice versa.

Rough Endoplasmic Reticulum

It Is The Endoplasmic Reticulum With Rough, Bumpy Or Bead-Like Look. Rough Look Is because of The Accessory of Granular Ribosomes To Its Outer Surface. Thus, It Is Likewise Called The Granular Endoplasmic Reticulum Rough Endoplasmic Reticulum Is Vesicular Or Tubular In Structure.

Functions of Rough Endoplasmic Reticulum

Synthesis of proteins

Rough endoplasmic reticulum is interested in the synthesis of proteins in the cell. It is included with the synthesis of generally those proteins which are produced from the cells such as insulin from p-cells of islets of Langerhans in pancreas and antibodies from B lymphocytes.

Ribosomes set up the amino acids into little systems of proteins and transport them into the rough endoplasmic reticulum. Here, the carbohydrates are contributed to the protein systems forming the glycosylated proteins or glycoproteins, which are set up in the form of reticular vesicles These vesicles are transferred generally to Golgi apparatus for more adjustment and processing. Couple of vesicles are transferred to other cytoplasmic organelles.

Destruction of damaged organelles

Rough endoplasmic reticulum likewise plays an essential role in the deterioration of damaged cytoplasmic organelles like mitochondria. It covers itself around the used- out organelles and forms a vacuole which is typically called the autophagosome. Autophagosome is absorbed by lysosomal enzymes (see listed below for information).

Smooth Endoplasmic Reticulum

It is the endoplasmic reticulum with smooth look. It is likewise called agranular reticulum. It is formed by lots of interconnected tubules. So, it is likewise called tubular endoplasmic reticulum.

Functions of Smooth Endoplasmic Reticulum

1. Synthesis of non-protein substance:
   Smooth endoplasmic reticulum is accountable for synthesis of non-protein substances such as cholesterol and steroid. This type of endoplasmic reticulum is plentiful in cells that are associated with the synthesis of lipids, phospholipids, lipoprotein substances, steroid hormones, sebum, and so on. In the majority of the other cells, smooth endoplasmic reticulum is less comprehensive than the rough endoplasmic reticulum.
2. Role in cellular metabolism:
   Outer surface of smooth endoplasmic reticulum consists of lots of enzymes which are associated with different metabolic processes of the cell.
3. Storage and metabolism of calcium:
   Smooth endoplasmic reticulum is the significant site of storage and metabolism of calcium. In skeletal muscle fibers, it launches calcium which is essential to set off the muscle contraction.
4. Catabolism and detoxification:
   Smooth endoplasmic reticulum is likewise interested in catabolism and cleansing of poisonous substances like some drugs and carcinogens (cancer-producing substances) in the liver.