Cell Biology Study Guide
Chapter 13 study guide
1. In the absence of targeting information, what is the default location of proteins synthesized by cytosolic ribosomes?
2. Two membrane-bound organelles that are responsible for making and modifying proteins are?
ER and Golgi- newly synthesized secretory proteins are first targeted to the ER, where they are folded and modified before exported to the Golgi for sorting
3. Name a few cytoplasmic proteins.
4. Name a few secretory proteins.
Plasma membrane proteins, ECM proteins, lysosomal proteins
5. What are the general chemical features of an N-terminal signal sequence that targets secretory proteins to the ER?
The SRP delivers the ribosome/nascent protein complex to the SRP receptor
Hydrophobic interaction
6. N-terminal signal sequences (know whether it is soluble or not in water, know the cytoplasmic protein that recognizes this sequence, and know the destination of the growing proteins that contains this N-terminal signal sequences).
7. Protein insertion into the mammalian ER membrane is typically? a. cotranslational. b. post-translational. c. pretranslational. d. quasitranslational
ANSWER: A
8. Describe what co-translational translocation is.
Translocation of secretory proteins into ER is coupled translation
Transport of secretory proteins into ER lumen begins while the incompletely synthesized protein is still bound to the ribosome
9. The two proteins that initiate the transfer of the N-terminal signal sequence of secretory proteins to ER include? 1.__________ 2.____________
SRP, SRP receptor
10. Describe the main function of SRP (Signal recognition particle).
SRP is a cytosolic ribonucleoprotein particle that binds to the ER signal sequence in a nascent protein and the large ribosomal subunit; forming a large complex. SRP targets the nascent protein ribosome complex to the ER membrane by bind to the SRP receptor
11. Which subunit of ribosome interacts with
1. In the absence of targeting information, what is the default location of proteins synthesized by cytosolic ribosomes?
2. Two membrane-bound organelles that are responsible for making and modifying proteins are?
ER and Golgi- newly synthesized secretory proteins are first targeted to the ER, where they are folded and modified before exported to the Golgi for sorting
3. Name a few cytoplasmic proteins.
4. Name a few secretory proteins.
Plasma membrane proteins, ECM proteins, lysosomal proteins
5. What are the general chemical features of an N-terminal signal sequence that targets secretory proteins to the ER?
The SRP delivers the ribosome/nascent protein complex to the SRP receptor
Hydrophobic interaction
6. N-terminal signal sequences (know whether it is soluble or not in water, know the cytoplasmic protein that recognizes this sequence, and know the destination of the growing proteins that contains this N-terminal signal sequences).
7. Protein insertion into the mammalian ER membrane is typically? a. cotranslational. b. post-translational. c. pretranslational. d. quasitranslational
ANSWER: A
8. Describe what co-translational translocation is.
Translocation of secretory proteins into ER is coupled translation
Transport of secretory proteins into ER lumen begins while the incompletely synthesized protein is still bound to the ribosome
9. The two proteins that initiate the transfer of the N-terminal signal sequence of secretory proteins to ER include? 1.__________ 2.____________
SRP, SRP receptor
10. Describe the main function of SRP (Signal recognition particle).
SRP is a cytosolic ribonucleoprotein particle that binds to the ER signal sequence in a nascent protein and the large ribosomal subunit; forming a large complex. SRP targets the nascent protein ribosome complex to the ER membrane by bind to the SRP receptor
11. Which subunit of ribosome interacts with