Some secretory proteins and some integral membrane proteins must pass through a membrane. A ribonucleoprotein known as the signal recognition particle (SRP) guides these proteins either to the plasma membrane (in bacteria) or the endoplasmic reticulum (in eukaryotes). Put the following steps of the membrane translocation of eukaryotic secretory proteins in order, starting after the signal peptide emerges from the ribosome and ending with the protein being transported by vesicles out of the endoplasmic reticulum. Signal peptide exits ribosome during translation. Translation resumes. Signal peptidase removes signal peptide from growing polypeptide. SRP binds to the signal peptide, and translation stops. Ribosome docks to a translocon. Growing polypeptide crosses the ER membrane through translocon. SRP moves the ribosome to the ER membrane. The remainder of the polypeptide is moved into the ER lumen. Protein is transported out of the ER.
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How does a plasma membrane protein become imbedded in the membrane? options: Ribosomes enter the endoplasmic reticulum and make the proteins within the ER. Once the signal peptide is translated, the ribosome complex is escorted to the ER, translation continues and the peptide is inserted through a pore in the membrane. Once completed, the protein is escorted to the PM and a chaperone protein pushes it in. Once the signal peptide is translated, the ribosome complex is escorted to the PM, translation continues and the peptide is inserted through a pore in the membrane. Ribosomes attach to the plasma membrane and translation of the peptide occurs directly on the PM.
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In a eukaryotic cell, what would be the location of protein synthesis for: Protein found in the matrix of mitochondria? A. Free Ribosomes in the Cytosol B. Surface of the ER C. Either of these D. None of these 2. In a eukaryotic cell, what would be the location of protein synthesis for: Nuclease in the lysosome? A. Free Ribosomes in the Cytosol B. Surface of the ER C. Either of these D. None of these 3. Place the following events involved in signal hypothesis in the correct sequence: A. Ribosome finishes/terminates translation on the RER B. SRP binds to the signal sequence C. mRNA leaves the nucleus D. Growing polypeptide chain enters the lumen of the RER E. SRP-Ribosome-mRNA binds to the SRP Receptor on the RER F. Ribosome begins the process of translation
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