Rough Endoplasmic Reticulum in Eukaryotic Cells

We know that the human body is supported and is alive because of the small microscopic unit we call a cell. Cells are incredible things that keep our entire body going and functioning at all times. We rely on these small units for a lot of things because they are always working to ensure our safety and our well being. But what exactly happens inside a cell? What happens inside a cell that leads to the right functioning of the human body? All of these questions are incredibly important for every student of Biology as they are focused on getting the answers to how life works in general. Cells exist in every living organism. They may vary in number but the major focus of the unit remains constant. As students of the subject, it is our responsibility that we understand and fully study this wonderful building block of life called the cell. There is a lot of knowledge that we know currently about the human cell, but at the same time, there is a lot that we do not know as well. The beautiful thing about all sciences is that we can always know a lot, but never know enough. The same applies here too. 

This article from Vedantu is going to focus on the Endoplasmic Reticulum. The Rough Endoplasmic Reticulum to be more precise. If you have made yourself aware and acquainted with the concept of cell organelles then you know that the Endoplasmic Reticulum can either be smooth or rough. This article’s main focus is going to be on the Rough Endoplasmic Reticulum, its functions, and what exactly is the main reason for it to be in our syllabus. Cell Organelles are always working for the benefit of our bodies. They are extremely hardworking as they are functioning all day long, carrying out life processes and sustaining our life on this planet. The functions of the Rough Endoplasmic Reticulum are going to be discussed as we go further in the article. 

We recommend that students take notes while reading and highlight all the key points that they may need for the future. 

Rough Endoplasmic Reticulum Definition and Function

The Rough Endoplasmic Reticulum comprises the endomembrane system. As the name suggests this reticulum appears rough when viewed under a microscope. This is because the Rough Endoplasmic Reticulum contains ribosomes and these are responsible for its rough appearance. As the Rough Endoplasmic Reticulum has ribosomes attached to it, they are a site of protein synthesis and the Rough Endoplasmic Reticulum works the same way. One more important function of the Rough Endoplasmic Reticulum is that it helps in giving rise to the Smooth Endoplasmic Reticulum. 

Endomembrane System

We have two types of cells in nature, they are prokaryotic and eukaryotic. The eukaryotic cells have the presence of a true nucleus. The prokaryotic cells do not possess a true nucleus. The prokaryotic cells are thought to be primitive cells. The eukaryotic cells have the presence of membrane-bound organelles. All the membrane-bound organelles have distinct structures and functions. The endomembrane system comprises the organelles that work in a coordinated manner. The mitochondria, chloroplast and peroxisomes do not work in a coordinated manner to any other organ, hence, they are not a part of the endomembrane system. We will study the function of the smooth Endoplasmic Reticulum, the function of the Rough Endoplasmic Reticulum, and the structure of the Endoplasmic Reticulum. 

Endoplasmic Reticulum

In this paragraph, we will learn about the function and structure of the Endoplasmic Reticulum. It is a network of reticulums that are just tiny tubular structures that are scattered around in the cytoplasm. The Endoplasmic Reticulum is formed by three types of structures: cisternae, tubules, and vesicles. 

• Cisternae

They are long and flattened structures. They also have sac-like and interconnected structures. The cells that are actively involved in protein synthesis is the place where we can find out these cisterns. They are also found in cells that have very active synthetic roles. Cells of the pancreas and the brain are examples where the cisternae are found. These cisternae have large subunits of ribosomes. The large subunit of ribosomes is the 60S.

• Tubules 

These form the reticular structure. Some of them have branches and some of them are unbranched. They form the reticular system along with the cisternae and vesicles. No ribosomes are present on them. They are found in abundance where the cells are involved in lipid and sterol synthesis. 

• Vesicles 

The vesicles are membrane-bound vacuolar structures. They are oval. In the pancreatic cells, they are found in abundance. The vesicles are the one and only endoplasmic reticular structures that are found in the spermatocytes. 

The Endoplasmic Reticulum helps in dividing the intracellular space into two distinct compartments. Those compartments are: 

• Luminal Compartment

This compartment forms and encloses the internal space. It is enclosed by the Endoplasmic Reticulum. 

• Extraluminal Compartment 

This space is present outside the Endoplasmic Reticulum. 

Types of Endoplasmic Reticulum

The Endoplasmic Reticulum is divided into two types. They are divided on the basis of the presence or absence of ribosomes on their surface. They are:

• Smooth Endoplasmic Reticulum

• Rough Endoplasmic Reticulum

Smooth Endoplasmic Reticulum

Here we will learn about the function of smooth Endoplasmic Reticulum. This reticulum is free from ribosomes. It is also known as the agranular reticulum. Smooth tubular structures appear when it is viewed under the microscope. Our muscle cells have rich amounts of the smooth Endoplasmic Reticulum. When it is present in muscles, it is known as the sarcoplasmic reticulum. 

The Function of Smooth Endoplasmic Reticulum are: 

• They help in the synthesis of lipids and steroids. 

• They help in the detoxification of drugs. 

• The synthetic products of the Rough Endoplasmic Reticulum are passed onto the Golgi complex via the smooth Endoplasmic Reticulum. 

• They help in muscle contraction. This is done by the release and uptake of calcium ions. 

Rough Endoplasmic Reticulum

The Rough Endoplasmic Reticulum contains ribosomes. The ribosomes are present on their surface. When it is seen under an electron microscope, rough patches appear therefore it is known as the Rough Endoplasmic Reticulum. It is also known as granular reticulum. They are extensive and are present in continuity with the outer membrane of the nucleus. The Rough Endoplasmic Reticulum contains two types of glycoproteins: Ribophorin-I and ribophorin-II. These are present for the attachment of ribosomal subunits. Mainly it is present for the attachment of the 60S subunit of 80S ribosomes. 

The Functions of the Rough Endoplasmic Reticulum are:

• As they have the presence of ribosomes, they are the site of protein synthesis. As they are sites of protein synthesis, they are found at places that are actively involved in protein synthesis. Not just synthesis, but they are present in sites of secretion of proteins. 

• They are responsible for giving rise to the Smooth Endoplasmic Reticulum. 

• They help in providing the precursors of the enzymes that are required for the formation of Golgi complexes. 

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Final Words

The Rough Endoplasmic Reticulum is a very crucial element of the cell that supports our very existence. It is wonderful how these small and tiny units inside the cell have a specific role to play in making our bodies better and helping us live healthily and a safe life. We hope that this article was successful in breaking this concept down and helped you in understanding the functions, characteristics, and basic information about the Endoplasmic Reticulum. The subject experts at Vedantu suggest that readers go through this article one more time to finally get a complete list of the topic one more time. Revision is key in concepts like this and that is what we recommend the most. With that being said, thank you so much for reading, and prepare well!