Question: 18. ___________ help pull proteins across the membrane and to refold the proteins once it is made…

18. ___________ help pull proteins across the membrane and to
refold the proteins once it is made. 19. What are the two
populations of ribosomes found in the cytosol? 20. What are the two
components that guide the ER signal sequence to the ER membrane?
21. What is the function of the ER and golgi apparatus? 22.
__________ makes most of the cell’s lipids and many of its
proteins. The proteins are made by __________ bound to the surface
of the __________. 23. Not all proteins that enter the ER are
__________ into the ER lumen. Some remain ___________ in the ER as
__________ proteins. 24. Describe coated vesicles. What role do
they play in secretory and endocytic pathways? 25. Distinguish
between exocytosis and endocytosis. 26. Proteins are covalently
modified in the ER by __________. How is this done? 27. If the
protein is not folded properly, it is kept in the ER by __________.
Ultimately the improperly folded protein do not reach the pm or are
not secreted are often ______ in the ER.