Endoplasmic Reticulum | Introduction,Types,Diagram & Function

By | September 10, 2019

Endoplasmic Reticulum

Endoplasmic Reticulum Definition:

Endoplasmic reticulum consists of flattened single membrane vesicles. These have the same lipid bilayer structure but thinner than the cell membrane (about 7mm). The ER is of two types; rough (RER) and smooth (SER). Only the rough of ER type has small granules known as ribosomes.

 

Endoplasmic Reticulum

Endoplasmic Reticulum Location

The ER processes most of the directions from the nucleus. As such, the ER surrounds the nucleus and radiates outward. In cells that secrete several materials for the rest of the body, the ER will account for over 500th of the cell.

In general, the nucleus expresses mRNA (messenger RNA), that tells the cell the way to build proteins. The RER has several ribosomes, that are the first location of protein production. This portion of the cell organelle creates proteins and begins to fold them into the right formation. The SER is the primary location for Lipids synthesis. As such, it doesn’t contain any ribosomes. Rather, it conducts a series of reactions that create the phospholipid molecules necessary to make numerous membranes and organelles.

The rough version of the ER is commonly nearer to the nucleus, whereas the SER is away from the nucleus. However, both versions are connected to each other and also with the nucleus through a series of little tubules.

Endoplasmic Reticulum Types†

There are two types Introduction of Endoplasmic Reticulum

  1. Rough Endoplasmic Reticulum
  2. Smooth Endoplasmic Reticulum

There are two major varieties of ER inside every cell Ė (SER) and (RER). Every type has distinct functions, and often, differing morphology. The SER is concerned in lipid metabolism and acts as the calcium (Ca) store for the cell. This can be significantly necessary for muscle cells that require Ca2+ ions for contraction. The SER is additionally concerned with the synthesis of phospholipids and sterol. It’s typically situated close to the fringe of the cell.

On the opposite hand, the RER is often seen near the nucleus. It contains membrane-bound ribosomes that provide it the characteristic Ďroughí appearance. These ribosomes are the points for making proteins that are intended for the lumen of the ER and are moved into the organelle as they’re being translated. These proteins contain a brief signal created by a number of amino acids in their N-terminus and are initially translated in the protoplasm.

Endoplasmic Reticulum

1. Rough Endoplasmic Reticulum Definition

RER Definition And Function are described below: Small granules like structure attached to the surface of endoplasmic reticulum due to this quality they are called Rough endoplasmic reticulum. These ribosomes are responsible for the synthesis of proteins. These synthesized proteins are either stored in the cytoplasm or extra proteins are transported to another part of the cell.

2. Smooth Endoplasmic Reticulum Definition

SER lacks ribosomal granules. They play a vital role in metabolism. They also provide mechanical support to the cell.

Endoplasmic Reticulum Diagram

Endoplasmic Reticulum

Smooth Endoplasmic Reticulum Function

The Functions of the Smooth ER are described below:

  1. Help in the metabolism of different molecules.
  2. Help in Lipid synthesis.
  3. Allow Glycogen synthesis within the cell.
  4. Help in Steroid synthesis like cholesterol, progesterone, testosterone, etc.

Rough Endoplasmic Reticulum Function

The Functions of Rough ER are described below:

  1. It provides the site for protein synthesis.
  2. It helps in the transport of proteins.

Endoplasmic Reticulum Structure And Function

Endoplasmic Reticulum

Endoplasmic Reticulum Function

Functions of Endoplasmic reticulum are described below:

  1. Functions of RER is concerned with protein synthesis while SER is concerned with lipids and glycoprotein synthesis.
  2. The cisternae (enclosed spaces) of the ER play a role in the exchange of material between the cell and the extracellular fluid.
  3. The exchange of material takes place through the process of pinocytosis done by the ER.
  4. Forms the skeletal framework.
  5. Allow active transport of cellular materials.
  6. Metabolic activities due to the presence of different enzymes.
  7. Provides an increased surface area for cellular reactions.
  8. Formation of nuclear membrane during cell division
  9. It is principally accountable for the transportation of proteins and other carbohydrates to a different organelle, which includes lysosomes, Golgi complex, cell membrane, etc.
  10. They provide the accumulated surface area for cellular reactions.
  11. They help within the formation of nuclear membrane throughout the cellular division.
  12. They play a significant role in the formation of the skeletal framework.
  13. They play a significant role within the synthesis of proteins, lipids, animal starch and alternative steroids like cholesterol, progesterone, androgenic hormone, etc.