Biology for Kids: Rough Endoplasmic Reticulum Function

in /by

What is Endoplasmic Reticulum? 

Endoplasmic Reticulum (ER) is an organelle inside the cytoplasm of an eukaryotic cell that has a network of tubules in it. Ribosomes are usually attached or involved in protein and lipid synthesis. Often, ER worked with Golgi apparatus (which takes packages and applies changes and transports it when necessary) and ribosomes. (Structure in cell that makes protein) 

What is Rough Endoplasmic Reticulum? 

Rough Endoplasmic Reticulum(RER) is a flat endoplasmic reticulum that had ribosomes attached to its outside surface. It belongs to a continuous membrane, the nuclear envelope surrounding the cell nucleus, and it’s name comes from the ribosomes covering it. What sets RER aside from the other ER, “Smooth Endoplasmic Reticulum (SER)” is that the SER has a smooth service and is in the shape of a tube. (It takes part in storing lipids) 

The ribosomes that connect to the RER known as, “membrane bound ribosomes.” This is because they attach to the outside of the ER on the cytosolic side firmly. In a liver cell alone, An average RER has around thirteen million ribosomes attached to it. 

What does Rough Endoplasmic Reticulum Do? 

RER is an essential part of the process of making protein. It takes part in folding protein as well as quality control, and finally dispatch. Endoplasmic reticulum occurs in not only humans, but in animals and plants as a site for making lipids and proteins. Those proteins are then sent to other organelles in the body. 

 Membrane bound ribosomes play a major role in maging protein. They are responsible for any assembly of the proteins. In the pancreas and digestive trap, a high amount of protein preduced as Enzymes. When the rough ER works with membrane bound ribosomes, they take polypeptides as well as amino acids from cytosol and continue to assemble protein. This includes recognizing a destination at an early stage. 

Proteins are made for a few organelles, including; Lysosomes, endosome, Plant vacuoles, plasma membrane, the Golgi apparatus, secretory vesicles, and even the Endoplasmic Reticulum itself. For the ER, proteins are delivered to the lumen. There, sugar groups are added to some proteins in the lumen which then form, glycoproteins.Other proteins, have metal groups added. 

From Rough Endoplasmic Reticulum to Golgi Apparatus 

For the most part, proteins are transferred to the Golgi apparatus. There it will be ”finished” and sent to set locations in the body. ER occurs in all the cell, but the closer to the nucleus or Golgi apparatus it is, the higher the density. 

The Golgi Apparatus and ER are close to each other, enough that observations show chemicals produced most likely directly pass to one another, and not going through the vestibules to transport to the cytoplasm. 

Protein Synthesis 

The process of protein synthesis begins by translation. This is when the protein is made from RNA as it grows. Depending on if it has a signal sequence at the end of its terminal or not, it binds to a signal recognition particle. This carries the ribosome to the RER membrane. After being bound, the signal recognition particle dissociates and does one of two things; it embeds into the RER Membrane or transmitted into the a lumen for the RER. 

In the lumen, proteins are modified a bit in various ways, like having signal sequences removed and glycosylation (The process in which oligosaccharides is added and produces a glycoprotein), the form of the protein may also change. 

From the RER, the molecule takes its three-dimensional conformation, from their proteins in the lumen move to a transitional region that most need ribosomes. Some proteins, secretory proteins come from sells which then are packed in vesicles and sent to the Golgi apparatus. Others stay in the ER to do their assigned jobs. 

The folding process of proteins in the Endoplasmic Reticulum to make important biochemical architecture. This provides “lock and key” as well as other linking sites. 

Also found in the lumen, there is a quality control checking process. Any proteins during the check that are found formed or folded wrong are denied. Those proteins are instead stored in the lumen or they are sent to be recycled and broken down into amino acids. Whenever a protein folds in a ay it shouldn’t, it's usually the result of faulty genetic coding. 

When there is something abnormal about the structure or function of an RER, it associates with certain diseases in people. Mostly, the excess of proteins in the RER that were not returned to the cytosol to be degraded. This brings stress, causing cell dysfunction, and cell death. 

An In-depth Overview of the Cell Membrane

in /by

What does the cell membrane do? Any idea as to some of the key functions of the cell membrane? Find out in a brief. 

The cell membrane can be defined as the semi-permeable membrane surrounding the cytoplasm of a cell. The lipid bi-layer that encloses the cell performs several vital functions we are going to discuss in a bit. But for now, let us look at the cell membrane structure to help us understand the functions of this thin sheet of tissue. 

The Cell Membrane Structure 

It goes without saying that the cell membrane tissue is composed of four different types of molecules: 

1. Lipids—lipids can make up anywhere between 20 and 80 percent of the membrane. The rest is cholesterol, carbohydrates as well as microtubule-associated proteins (MAPs). Lipids help to give the cell membrane its flexibility, which is vital for its functions. 

Phospholipids are a special type of lipids that are extremely important for the membrane. These lipids feature hydrophilic head areas and hydrophobic tail areas. (Hydrophilic means attracted to water whereas hydrophobic means repelled by water). 

Nonetheless, the lipids work by forming a lipid bi-layer whereby their head areas spontaneously arrange to face the aqueous cytosol (the fluid found inside the cell) and the extracellular(outside of the cell) fluid. On the other hand, their tail areas face away from the cytosol and extracellular fluid. It should be noted that the semi-permeable bi-layer allows only certain molecules to diffuse across the membrane. 

Additionally, the lipid component also contains cholesterol and glycolipids molecules whose primary functions are to protect the cell membrane from becoming stiff and enable the cell to recognize other fellow cells of the body. 

2. Proteins—the cell membrane has two types of proteins; 

• Peripheral membrane proteins.

• Integral membrane proteins. 

The former are exterior to the membrane and hooked to it by way of interaction with other proteins. On the other hand, the latter are planted into the membrane and most pass through the membrane with portions of them exposed on both sides of it. 

Peripheral and integral proteins perform important functions. These including monitoring and maintaining the chemical environment of the cell, helping in the transfer of molecules across the membrane and giving it a structural support. 

What Does the cell membrane Do? 

The tissue plays two primary roles: 

1. It acts as the cell’s physical barrier, barring substances that could get into the interior of the cell to cause damage. 

2. The cell membrane controls the process of the exchange of materials with the external environment. This is extremely crucial since some substances could easily disrupt things, causing a lot of problems as a result. 

Cell membrane Disorders 

Can the cell membrane be affected by any diseases? Of course, yes. The membrane is prone to any disease that may compromise the integrity of the cell. One common cell membrane disorder is cystic fibrosis. 

This is a genetic disorder that affects the cell’s integrity by interfering with its ability to secret sufficient water. When it occurs in the lung cells, the mucus becomes extremely thick. Consequently, the patient will suffer from a wide variety of symptoms including but not limited to wheezing, breathing with a difficulty, exercise intolerance, and persistent cough. N addition, they become susceptible to infection due to excessive mucus build up. If not treated properly, this could result in a loss of life. 

Treatment Options 

• Administration of antibiotics to treat and prevent chest infections.

• Administration of drugs to reduce the mucus thickness and ease the cough up.

• Administration of drugs to expand the airways and reduce inflammation.

• Application of special techniques using certain devices to help eliminate mucus from the lungs.

• A lung transplant operation, especially if the organs have become severely damaged. 

Final Thoughts 

It is my hope that now you understand what the cell membrane really is, including its structures plus the primary roles it plays. Finally, I believe you are now aware of one of the common cell membrane disorders and the possible treatment options available. It is important to note, however, that most cell membrane diseases are genetically passed down from a parent to a child. Without nothing more to add, this article comes to an end. 

An In-depth Look at the Endoplasmic Reticulum

in /by

Hello learner! It is nice to have your attention to basic biology once again. Today I want to teach you about a very crucial organelle in the cells of all living things called endoplasmic reticulum. First though, I hope you know what an organelle is. If not, this is simply an organized or specialized structure within a living cell. I hope this is not beginning to sound too technical and above your level. My intention is to keep it pretty simple and straightforward without deviating from basic in biology. So, without further ado, let us get started with the definition of the endoplasmic reticulum. 

What Is Endoplasmic Reticulum? 

The endoplasmic reticulum (ER) is an important type of organelle found in eukaryotic cells that forms an interconnected network of tube-like structures called cisternae. Eukaryotic cells are simply those whose nucleus is enclosed within as opposed to outside the membranes(prokaryotic cells). 

There are two types of endoplasmic reticulum i.e smooth ER and rough ER. The former lacks microorganic particles consisting of ribonucleic acid(RNA) and associated proteins, known as "ribosomes". RNA is simply a nucleic acid present in all living cells, which acts as a chemical messenger carrying instructions DNA instructions in the process of protein synthesis. In addition, smooth ER functions in lipid synthesis but not metabolism, detoxification or the production of steroid hormones. 

The rough ER, on the other hand, contains ribosomes in the outer surface for protein synthesis. That is the primary difference between the two types of ERs. 

It goes without saying that endoplasmic reticulum is present in almost every type of eukaryotic cell except sperm cells as well as red blood cells. 

Functions of the Endoplasmic Reticulum 

What is the function of the endoplasmic reticulum? This is a common exam question for learners who are studying basic biology. Who knows, it could even feature in your next paper. Therefore, I want you to be extremely focused and attentive for the next part of this article. 

The endoplasmic reticulum plays an important role in keeping you alive and serves many general functions essential for the cell. These functions include the folding of protein molecules in sacs known as "cisternae" and the transport of synthesized proteins in special vessels called "vesicles" to the Golgi complex/apparatus. The Golgi Apparatus then processes the semi-finished proteins and finalizes them, before releasing them to the body. 

Endomembrane System Dysfunction 

Just like organs, organelles can deteriorate in health and eventually become dysfunctional. A dysfunctional endomembrane system comprising of unhealthy endoplasmic reticuli can lead to a wide variety of neurological disorders. These include Alzheimer's disease, sleep apnoea, cerebral ischemia, multiple sclerosis, the prion diseases, amyotrophic lateral sclerosis, epilepsy, and familial encephalopathy with neuroserpin inclusion bodies (FENIB). If not addressed in time, some of these neurological disorders can lead to serious problems such as temporary/permanent madness, blindness, and deafness. Stroke is another potential threat. 

It is my hope that you now understand what the endoplasmic reticulum is and the primary function it serves. What does the endoplasmic reticulum do? It transports semi-processed protein molecules to the Golgi complex for final processing before they are released to the body. The membrane system, which controls the ER and the Golgi apparatus can deteriorate in health and become dysfunctional. If that happens, a number of neurological health conditions can occur, needing immediate attention. Some of these disorders, if not addressed in time, can lead to serious effects like madness, blindness, deafness and even stroke. 

What You Have Learned 

• There are two types of endoplasmic reticuli; smooth endoplasmic reticulum and rough endoplasmic reticulum.

• Smooth endoplasmic reticulum lacks ribosomes but rough endoplasmic reticulum contains ribosomes. 

• Ribosomes are microscopic particles that contain ribonucleic acid(RNA). 

• RNA act as a messenger carrying instructions from DNA for controlling the process of protein synthesis. 

• The endoplasmic reticulum is present in every eukaryotic cell except sperm cells as well as red blood cells. 

• The primary functions of the endoplasmic reticulum are to fold synthesized protein molecules and transport them to the Golgi complex/apparatus for processing before being released to the body. 

• The job of the Golgi Apparatus is to process and finalize semi-finished proteins and then release them to the body. 

9 Main Functions of Golgi Bodies

in /by

Golgi bodies commonly referred to as Golgi apparatus are specialized structures within the cell that handle specific roles and assist the cell to function. These organelles, which form a considerable part of the cell’s endomembrane system, are mostly found in eukaryotic cells. Like any other organelle, the Golgi complex carries various functions within the cell, some of which have been discussed below. 

1. Absorption of Compounds 

Golgi bodies are connected with storage and absorption lipids, which help them to form an essential part of the absorption system within the cell. They help in absorbing complex compounds such as sugar. According to Hirsch, the Golgi complex also helps in the absorption of pure elements such as copper and gold, which are essential metals in the body. Additionally, Golgi bodies help in removal of water from various products, especially during the formation of secretory granules. 

2. Help in Enzyme Formation 

Golgi complex is responsible for the formation of most of the enzymes in the cells and other areas that breakdown food into its constituent components. Enzymes are biological catalysts that support chemical reactions in the cells. Most of these biological reactions take place in various parts of the body such as mouth, stomach, and the small intestines. Pancreatic digestive enzymes such as pancreatic amylase are produced by Golgi and then released into pancreatic ducts. 

3. Formation of Secretion and Secretory Vesicles 

Besides being involved in multiple cell functions, the primary role of Golgi is secretion. Movement of materials from one place of the cell to the other is an important role that must be guided by specialized cell organelles. Golgi complex forms secretory vesicles which are used as the medium for secretions. Most of the secretions, especially those from the rough endoplasmic reticulum, move through Golgi apparatus and finally through the plasma membrane to the adjacent cells. 

4. Production of Hormones 

Hormones are chemical secretions from the cell that help to trigger the performance of various body tissues and organs to react in a particular way. Like other secretions, hormones are produced by Golgi apparatus. This is an indication that any disturbance of Golgi could lead to low enzyme production, which could be catastrophic. 

5. Formation of Intracellular Crystals 

Within the cells, there are multiple crystals which are components of secretions and provide a conducive medium for chemical reactions. These crystals contain large quantities of iron and proteins and are formed by Golgi bodies. Most of these crystals do not have an enclosing membrane. They also play a significant role in secretory activities. 

6. Formation of Plant Cell Wall 

Golgi bodies play a secondary role in the formation of plant cell walls. They synthesize all polysaccharides within the plant cells, which are the major components of the cell wall. Microfibrils, hemicelluloses, and pectin are synthesized by Golgi apparatus and then packed in vesicles for secretions. These materials are later released through secretion to the cell wall where they are major components. 

Golgi is also involved in mitotic cell division where they form a cell plate. Through secretion and deposition of hemicelluloses and pectic substances, the cell plate is thickened and enlarged and later deposited on the outermost part of the plant cell as the cellulose cell wall. 

7. Glycoproteins Secretions 

Like other proteins, glycoproteins are formed by the Golgi complex. Most of the protein products are attached to carbohydrates to form highly concentrated protein components. Concentrated protein products are stored on the edge of Golgi bodies after which they will be released through secretions on a need basis. 

8. Storage of Protein 

Vesicles and vacuoles are the major components of the Golgi complex, and they act as the major storage areas for proteins and other lipids. Protein or lipids synthesized within the cell are all stored by Golgi, and they are later used in secretions. 

9. Formation of Milk Protein Droplets 

This does not occur in the cells of most animals but occurs in mammary glands of lactating mice. Most of the proteins produced are highly related to the Golgi complex. The milk droplets open on the cell surface by fusion and enter the cell through the plasma membrane. 

Like other important cell organelles, Golgi bodies are very important because they handle complex roles within the cell. Secretion, which is their main role, almost controls all functions of the cell. Other important roles of the Golgi complex include the formation of acrosomes among other functions.