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-Some proteins are targeted to the ER by a signal sequence which is recognised by an SRP (signal recognition particle). The protein is translated into the ER through the translocon.
Modifications:
-Signal sequence is cleaved by a signal transpeptidase.
-Protein folding is aided by molecular chaperones such as BiP and Calnexin.
-O linked and N linked glycosylation occurs (N-linked most common).
-Di sulfide bond formation occurs (highly reducing environment inside the ER unlike in the cytoplasm)
- GPI anchor modifications
-ubiquitination - and then proteins can be degraded by the proteosome in the cytosol. Occurs if protein is not folded correctly. The unfolded response can also occur.
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∙ 12y ago
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What does ER stand for in science?
Emergency Room
What is the observation in a science project?
it is what you observe, er, see.
What is the sun's life cycle in relationship with the moon?
the wasc ghj mnhh gg er the wasc ghj mnhh gg er
What is the cells delivery system abbreviation?
ER for Endoplasmic Reticulum
What is the syllabication of cleaner?
The syllabication of "cleaner" is "clean-er."
Why post-translational modification of protein does not occur in prokaryotes?
introns and exons are absent in prokaryotic rna hence processing not necessary
What combines with proteins?
Proteins are polymer of amino acids produced in ribosomes. During post translational modification in ER protein can be attached to glycosyl groups, phosphates, or any prosthetic group such as esters, thioesters, amides, methyl groups and so on. This in turn make a protein mature after proper folding in Golgi bodies.
What receives newly synthesized proteins?
Most of the proteins that are being synthesized come from the ribosomes attached to the rough endoplasmic reticulum (ER). After the protein synthesis is completed, the new protein molecule goes into the ER in order to complete their synthesis (sometimes it has to be passed through a process called "post-translational modification", e.g., the addition of a carbohydrate residue) that is taking place in the lumen of the ER. Afterwards, the complete protein (if it has to be secreted) goes to the Golgi apparatus and to the plasma membrane.
Why protein produced by free ribosomes stay inside the cell?
Because they are not on the path to modification in the rough ER and further modification and shipping that happens in the Golgi body. Remember, the rough ER is called that because it is studded with ribosomes and the building polypeptide chain is threaded directly into the ER for completion and modification. From the ER to the Golgi is the dedicated path of further modification and shipping; in and our of the cell. Free ribosomes are not on this pathway and are folded without extensive modification and no shipping center to be shipped from.
The job of the endoplasmic reticulum?
Mainly. The rough ER; protein modification. The smooth ER; lipid manufacturing.
Which organelle is involved in the modification and transport of protein?
the smooth and rough(ER) AS WELL AS THE NUCLEUS the smooth and rough(ER) AS WELL AS THE NUCLEUS
What continues and finishes some of the ER functions?
The Golgi apparatus finishes processing, modification or packaging a protein after it leaves the ER.
What is the function of endoplasm?
The rough ER is the site of protein modification and folding of proteins, if they need folding. The smooth ER is the site of lipid and steroid synthesis.
What is the endoplasm function?
The rough ER is the site of protein modification and folding of proteins, if they need folding. The smooth ER is the site of lipid and steroid synthesis.
What happen when there are mistakes made during protein synthesis?
The ribosomes are the " workbench " of protein synthesis with the rough ER accepting some polypeptide chains from the ribosomes studding it into it's lumen for modification. Then the modified proteins are shipped to the Golgi for further modification and shipment to wherever they are needed.
What does the endoplasmic do in a animal cell?
Protein modification, basically Proteins are threaded right into the rough ER from ribosomes, modified, attachment of sugars for instance, then shipped to the Golgi for further modification and final destination shipping.
Why proteins made by free ribosomes free of carbohydrates?
These proteins are not directed to the Golgi for modification. there are two paths for synthesis of proteins: 1) By free ribosomes in the cytosol. Protein is left in the cytosol with no carbohydrate modifications 2) By ribosomes bound to the ER. The protein is transported into the ER during synthesis and transported to the golgi for modification.
