Rough+ER

Rough Endoplasmic Reticulum (ER)



Endoplasmic Reticulum The Endoplasmic Reticulum, or ER, was first discovered in 1945 by a scientist named Keith Porter and his associates,Albert Claude, Brody Meskers, and Ernest F. Fullam. They discovered ER when observing chicken fibroblasts through an electron microscope. The Endoplasmic Reticulum simply means “Network within the plasma of a cell”. The main origins of the name come from the Greek and Latin languages. From Greek, endon, which means anything within plasma. From the Latin language, Reticulum, meaning network.

The Endoplasmic Reticulum is a system of canals inside the cell and is also a network of membranes called Cisternae. These membranes are continuous with in the ER and have an outer nuclear membrane. The Endoplasmic reticulum works to Manufacture and package materials in the cell.” The [|phospholipid membrane]  encloses the cisternal space (or lumen), which is continuous with the [|perinuclear space]  but separate from the [|cytosol] ” ( [] ).

The Endoplasmic Reticulum main function is to f old the protein molecules into Cisternae, or tiny sacs like structures that are bonded together by a Cytoskeleton. The ER is also is used for transporting proteins to the Golgi apparatus. This organelle is found in most Eukaryotic cells with exceptions of Spermatozoa (motile sperm cell) and Red blood cells.

*There are two types of ER, Smooth and Rough*.

Rough ER Rough ER, RER, is different from Smooth ER, SER, as it has ribosomes the outer surface, which gives the ER its name. The SER does not have ribosomes on its surface. The ribosomes found on the surfaces are mostly responsible for the assembly of proteins.The Rough Endoplasmic Reticulum's ribosomes are also responsible for the quality control, folding, production and release of proteins.They can also act as the sights for Protein Synthesis. The assembly of proteins can also be referred as “Translation”. The ribosomes however, are not a stable part of the organelles structure, as they constantly are moving around, being bound, and getting released. The RER is also directly attached to the nuclea r envelope, connection between the Perinuclear space and lumen, that surrounds the nucleus so movement of molecules through both membranes goes easier.

Analogy: Speed bumps: Road Speed bumps lay on the surface of the road. Ribosomes: RER

“The rough ER working with membrane bound ribosomes takes polypeptides and amino acids from the cytosol and continues protein assembly including, at an early stage, recognizing a ‘destination label’ attached to each of them” []

Words to kno w: Cisternae- The sacs formed by the double membranes of smooth and rough ER.

Lumen- an enclosed network of vehicles, flattened cisternae, and tubules that produces secretory products, such as hormones.

Bonus Facts…

* The Ribosomes on the RER can also be Membrane Bound.

* About 50% of the cells membranes mass is thanks to the Endoplasmic Reticulum

* The RER has a higher density near the Golgi Apparatus and the Nucleus.

Work Cited:

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