Rough endoplasmic reticulum function
Golgi apparatus function
The electron microscope made possible the study of the morphology of the ER in the s, when it was given its present name. Key Takeaways A cell's endoplasmic reticulum ER contains a network of tubules and flattened sacs. Regina Bailey is a science writer and educator who has covered biology for ThoughtCo since Learn more about the electron microscope. What is the difference between smooth and rough endoplasmic reticulum? Rough Endoplasmic Reticulum The rough endoplasmic reticulum manufactures membranes and secretory proteins. Proteins secreted from the Golgi apparatus are directed to lysosomes or to the cell membrane; still others are destined for secretion to the cell exterior. In the lumen some proteins have sugar groups added to them to form glycoproteins. Initial glycosylation as assembly continues. Ribosomes also create proteins which are embedded into the rough endoplasmic reticulum for further processing integral membrane proteins. Some proteins, such as secretory proteins, which are released by cells, are packaged in vesicles and move to the Golgi apparatus.
Pietro M. Integral membrane proteins that stay embedded in the membrane as vesicles exit and bind to new membranes.
Proteins are subjected to a quality control check and any that are found to be incorrectly formed or incorrectly folded are rejected.
Function of endoplasmic reticulum in points
Changes in protein content may occur without noticeable structural changes. Many of the proteins are produced in quantity in the cells of the pancreas and the digestive tract and function as digestive enzymes. The ribosomes on rough ER specialize in the synthesis of proteins that possess a signal sequence that directs them specifically to the ER for processing. Rough ER looks like sheets or disks of bumpy membranes while smooth ER looks more like tubes. Some have metal groups added to them. In most cells the smooth endoplasmic reticulum abbreviated SER is scarce. The reason why it is rough endoplasmic reticulum is because of the ribosomes attached to the endoplasmic reticulum. Some proteins, such as secretory proteins, which are released by cells, are packaged in vesicles and move to the Golgi apparatus.
The protein might work well without the amino acid but the very exacting service provided by the quality control section spots the error and rejects the protein retaining it in the lumen of the rough ER.
Rough ER RER was also mentioned in the section on ribosomes and is very important in the synthesis and packaging of proteins. In cells of the liver, SER contributes to the detoxification of drugs and harmful chemicals.
The RER is generally a series of connected flattened sacs. Rough ER contains attached ribosomes while smooth ER does not. These ribosomes are constantly being attached and detached from the ER because they are not part of the stable organelle.
In particular, the accumulation in the RER of misfolded proteins, which normally are returned to the cytosol, where they are degraded, can result in ER stress, leading to cell dysfunction and cell death.
based on 108 review