Endoplasmic Reticulum

Introduction

The endoplasmic reticulum is the cellular component, it is present in most of the eukaryotic cells. It performs various functions for cells. It can be named as the transportation system of the cell. The endoplasmic reticulum is subdivided into two types, one is Rough faced endoplasmic reticulum and another type is smooth-faced endoplasmic reticulum, both types of endoplasmic reticulum are important organelles of cells. So below, we have discussed the endoplasmic reticulum, its Subdivision, functions, structures, importance, etc. The endoplasmic reticulum is part of the syllabus for standard XI science stream students, so it is crucial to understand it. Hence, Unacademy is here for you with the article on endoplasmic reticulum which has covered most aspects of the topic. Let’s discuss

About Endoplasmic Reticulum

The endoplasmic reticulum is the organelle that is present in almost every eukaryotic cell. Endoplasmic reticulum is generally divided into two categories, RER and SER. The endoplasmic reticulum is like a sac in structure. The continuous network of these sacs of membranes is termed cisternae. The formation of membrane sheets and cisternae in the endoplasmic reticulum, which performs duplication (synthesis) of cholesterol and lipids, folding and transportation of various proteins, packaging, manufacturing, etc. throughout them (sacs and membrane sheets). The endoplasmic reticulum performs continuous folding originating from near the nucleus of the cell and spreading its membranes in the whole cell. Both types of endoplasmic reticulum remain absent in sperm cells and red blood cells as these cells don’t need to perform synthesis or transportation of proteins for their functioning. However smooth endoplasmic reticulum and rough endoplasmic reticulum both perform different functions for cells.

History

The endoplasmic reticulum was first seen by great scientist Garnier in the year 1987. After, with the help of an electron microscope, its tail-like fabrics were observed who were interconnecting to each other, famous scientist Keith porter was the observer of that fabrics. The term Reticulum refers to ‘Network’; it was coined by Keith Porter in 1953. Thompson and Porter are known as the father of the endoplasmic reticulum.

Rough endoplasmic reticulum (RER)

Rough endoplasmic reticulum has the ribosomes studded in its outer surface which are there to secrete proteins in a cell. Hence, giving out an unsmooth structure and termed it as the rough endoplasmic reticulum. About 13 million ribosomes are studded in the layers of the endoplasmic reticulum of liver cells and the rough endoplasmic reticulum location is somewhere near the nucleus or Golgi apparatus of the cell. The rough endoplasmic reticulum also participates in developing smooth endoplasmic reticulum.

Rough endoplasmic reticulum structure

• The protein-releasing ribosomes are found in the rough endoplasmic reticulum’s outer layer.
• The rough endoplasmic reticulum is joined just below the nucleus surface.
• It has a tiny membrane vesicle nearby which gets pushed down after protein synthesis.
• It has a continuous chain of flattened membranes around the cell, the network of those membranes is called cisternae.
• The rough endoplasmic reticulum’s surface is likewise studded with integral membrane proteins.

Rough endoplasmic reticulum functions

• To synthesize the proteins and transport them to hormones, the liver, and other body organs.
• To send signals to the nucleus in case of imbalance in protein production and hence helping.
• To build the chain of amino acids.
• To perform packaging and transport various proteins.
• Rough endoplasmic reticulum’s structure gives the advantage to the endoplasmic reticulum to control protein processing.
•  Vesicles that get pushed down after protein synthesis exit and form other membranes.

Smooth endoplasmic reticulum (SER)

Smooth endoplasmic reticulum’s surface structure is opposite of rough endoplasmic reticulum, it doesn’t have any ribosomes studded in it and hence smooth surface is observed. It is termed a smooth endoplasmic reticulum due to its smooth surface. The smooth endoplasmic reticulum is found in the case of the nucleus. Its membranes are found in the cell periphery. The smooth endoplasmic reticulum has tabular-like sacs present all over the cell which helps the cell to perform many functions. The smooth endoplasmic reticulum is found in abundant quantities near the cells which secrete cells for reproductive organs and oil glands. Here are smooth endoplasmic reticulum functions and their structure.

Smooth endoplasmic reticulum Structure

• It has tabular-shaped sheets around the cells which perform various functions for the cell.
• its surface is smooth since there are no ribosomes upon that.
• Smooth endoplasmic reticulum position is likewise close to rough endoplasmic reticulum location since it contains no ribosomes on the surface.

 Smooth endoplasmic reticulum functions

• To perform the duplication of steroids, phospholipids and lipids.
• The rough endoplasmic reticulum’s materials are shipped to other cell organelles by the smooth endoplasmic reticulum.
• To cleanse all the contents of harmful products of alcohol and drugs.
• It increases the metabolism of carbohydrates content present in cells.
• It regulates the cell’s calcium ion concentration..
• The smooth endoplasmic reticulum participates in an important process of the body called gluconeogenesis which produces glucose.
• Its smooth surface gives the advantage to storing main enzymes and the products with cells.
  

  Key differences between RER and SER

  Rough endoplasmic reticulum	Smooth endoplasmic reticulum
  Ribosomes are present at the surface.	There are no ribosomes on the surface.
  They form chain-shaped flattened sacs membranes.	They form a chain of tabular sheets of membrane throughout the cell.
  They form cisternae.	They form vesicles.
  The rough endoplasmic reticulum functions the transport in the cell.	Smooth endoplasmic reticulum functions the storage in cell.

  Ultrastructure of endoplasmic reticulum The general structure of the endoplasmic reticulum consists of a thick wall of membrane and after this wall, they have another two walls present in their structure one inside and one outside of it. They also have various proteins present in their surface and inner wall.

  Conclusion

  Above from here, we came through the Endoplasmic reticulum, we learned their types, differences, functions, structures, and other small aspects as well. The endoplasmic reticulum covers some part of the class XI science syllabus and is great to learn, so it was the only motive to present this article. There are many other cell-related and other mechanisms covered on Unacademy. This brief note about the Endoplasmic reticulum can help you to understand the Endoplasmic reticulum’s concepts more easily.