Exam 3: RR (5)

Card Set Information

Author:
DesLee26
ID:
242453
Filename:
Exam 3: RR (5)
Updated:
2013-10-23 19:43:54
Tags:
Required Reading
Folders:

Description:
Mickle
Show Answers:

Home > Flashcards > Print Preview

The flashcards below were created by user DesLee26 on FreezingBlue Flashcards. What would you like to do?


  1. a.      Glycosylation in the RER
                                                                  i.      nearly all proteins produced on membrane-bound ribosomes—whether integral components of a membrane, soluble lysosomal or vacuolar enzymes, or parts of the ECM—become __
    1.      __ have key roles in the function of many __, particularly as bidning sites in their interactions with other __, as occurs during many cellular processes
    • glycoproteins
    • carbohydrate groups
    • glycoproteins
    • macromolecules
  2.                                                               i.      they also aid in the __ and __of the protein to which they are attached
    1.      the sequences of sugars that comprise the __ of __are highly specific; if the __are isolated from a purified protein of a given type of cell, their sequence is consistent and predictable
    • proper folding and stabilization 
    • oligosaccharides
    • glycoproteins 
    • oligosaccharides
  3.                                                               i.      the addition of sugars to an __chain is catalyzed by enzymes called __, each of which transfers a specific monosaccharide from a __sugar to the growing end of the carb chain
    1.      the sequence in which they are transferred during assembly of an oligosaccharide depends on the __ that participate in the process
    • oligosaccharide 
    • glycosyltransferases
    • nucleotide 
    • sequence of action of glycosyltransferases
  4. a.      this in turn depends on the location of specific __within the various memrbaens of the __
                                                                                                                                          i.      thus, the arrangement of sugars int eh oligosaccharide chains of a glycoprotein depends on the __ of particular __in the __
    • enzymes 
    • secretory pathway
    • spatial localization
    • enzymes 
    • assembly line
  5.                                                               i.      the initial steps in the assembly of __ of both soluble proteins and integral membrane proteins
    1.      __, or __, segment of each carb chain is not assembled on the protein itself but put together independently on a __ and then transferred, as a __, to specific __ of the polypeptide
    • N-linked oligosaccharides
    • basal
    • core
    • lipid carrier
    • block
    • asparagines residues
  6. a.      this lipid carrier, which is named __, is embedded in the ER membrane
                                                                                                                                          i.      sugars are added to the __ molecule one at a time by membrane-bound __
    • dolichol phosphate
    • dolichol phosphate
    • glycosyltransferases
  7. 1.      this part of __ process is invariant; in mammals, it begins with the transfer of __, then __ and three __units in the precise pattern, which is then transferred by the ER enzyme __from __ to certain __ in the nascent polypeptide as the polypeptide is being translocated into the eR lumen
    • glycosylation
    • N-acetylglucosamine
    • nine mannose
    • glucose 
    • oligosaccharyltransferase 
    • dolichol phosphate
    • asparagines
  8.                                                               i.      mutations that lead to the total absence of __ cause the death of embryos prior to __
    1.      mutatiosn that lead to partial disruption of the __pathway in the ER are responsible for serious inherited disorders affecting nearly every organ system
    a.      these diseases are called __ and they are usually identified through blood tests that detect abnormal __ of serum proteins 
    • N-glycosylation
    • implantation
    • glycosylation 
    • Congenital Diseases of Glycosylation
    • glycosylation
  9.                                                               i.      shortly after it is transferred to the nascent polypeptide, the __ undergoes a process of __
    1.      this modification begins int eh ER with the enzymatic removal of two of the three __
    a.      this sets the stage for an important event in the life of a newly synthesized __in which it is screened by a system of quality control that determines whether or not it is fit to move on to the next compartment of the __
    • oligosaccharide chain
    • gradual modification
    • terminal glucose residues
    • glycoprotein 
    • biosynthetic pathway
  10.                                                                                                                                       i.      to begin this __process, each __, which at this stage contains a single remaining glucose, binds to an __
    1.      removal of the remaining glucose by __ leads to release of the glycoprotein from the __
    • screening 
    • glycoprotein
    • ER chaperone
    • glucosidase II
    • chaperone
  11. a.      if a __ at this stage has not completed its folding or has misfolded, it is recognized by a __that adds a __ back to one of the __residues at the exposed end of the recently trimmed oligosaccharide
                                                                                                                                                                                                                  i.      __recognizes incompletely folded or misfolded proteins because they display exposed __ that are absent from properly folded proteins
    • glycoprotein
    • conformation-sensing enzyme (UGGT) 
    • single glucose residue
    • mannose 
    • UGGT 
    • hydrophobic residues
  12. 1.      once glucose residues added, the “__” glycoprotein is recognized by the same __, which give the protein another chance to fold properly
    a.      after some time with the __, the added glucose residue is removed and the __ checks it again to see if it has achieved its proper 3D structure
                                                                                                                                                                                                            
    • tagged
    • ER chaperones
    • chaperone
    • conformation-sensing enzyme
  13.                                                                                                                                                                                                               i.      if it is still partially unfolded or misfolded, another __ is added and the process is repeated until, eventually, the __has either folded correctly and continues on its way, or remains misfolded and is destroyed
                                                                                                                                                                                                                ii.      studies say the decision to destroy the defective protein begins with the __ that trims a __ from an exposed end of the __of a protein that has been in the ER for an extended period
                                                                                                                                                                                                              iii.      once one or more of these __ have been remove, the protein can no longer be recycled and, instead, is sentenced to degradation
    • glucose residue
    • glycoprotein 
    • activity of a slow-acting enzyme in the ER
    • mannose residue
    • oligosaccharide 
    • mannose resiudes
  14.                                                               i.      Mechanisms that Ensure the Destruction of Misfolded Proteins
    1.      misfolded proteins are not destroyed in the ER, but instead are __
    2.      once in the cytosol, the __ are removed, and the __are destroyed in __, which are protein-degrading machines; this process is called __
    a.      it ensures that aberrant proteins are not transported to other parts of the cell, but it can have __
    • transported into the cytosol by a process of dislocation
    • oligosaccharide chains
    • misfolded proteins 
    • proteasomes
    • ER-associated degradation (ERAD)
    • negative consequences
  15. 1.      under certain circumstances, misfolded proteins can be generated in the __ at a rate faster than they can be __to the cytoplasm
    a.      accumulation of misfolded proteins, which is potentially lethal to cells, triggers a comprehensive “__” within the cell called __
                                                                                                                                          i.      the ER contains __ that monitor the concentration of unfolded or misfolded proteins in the ER lumen
    1.      the sensors are normally kept in an __ state by molecular __, particularly __
    • ER
    • exported 
    • plan of action
    • unfolded protein response (UPR)
    • protein sensors
    • inactive
    • chaperones
    • BiP
  16.                                                                                                                                       i.      if circumstances should lead to an accumulation of __, the __ molecules in the __ are called into service as __ for the misfolded proteins, rendering them incapable of inhibiting the sensors
    • misfolded proteins
    • BiP
    • ER lumen
    • chaperones
  17.                                                                                                                                       i.      activation of the __leds to a multitude of signals that are transmitted into both the nucleus and cytosol and result in :
    1.      the __ whose encoded proteins have the potential to alleviate stressful conditions within the ER
    • sensors 
    • expression of hundreds of different genes
  18. a.      these include genes that encode:
                                                                                                                                                                                                                  i.      __ that can help misfolded proteins reach the native state
                                                                                                                                                                                                                ii.      proteins involved in the __
                   iii. proteins involved in the __ of abnormal proteins 
    • ER-based molecular chaperones
    • transport of the proteins out of the ER
    • selective destruction
  19. 1.      __of a key proiten is required for protein synthesis
    a.      this modification inhibits __ and decreases the flow of newly synthesized proteins into the ER
                                                                                                                                                                                                                  i.      this gives the cell an opportunity to remove those proteins that are already present in the __
    • phosphorylation 
    • protein synthesis
    • ER lumen
  20.                                                               i.      The __ is more than a __ mechanism; it also includes the activation of a pathway that leads to the __
    1.      it is presumed that the __provides a mechanism to relieve itself of the stressful conditions
    a.      if these corrective measures are not successful, the __ is triggered and the cell is destroyed
    • UPR
    • cell-survival
    • death fo the cell
    • UPR 
    • cell-death pathway
  21. a.      From Erà Golgi
                                                                  i.      the __ contain specialized exit sites that are devoid of ribosomes and serve as places where the__ in the __pathway are formed
                                                                ii.      soon after they bud from the ER membrane, __ fuse with one another to form larger vesicles and interconnected tubules in the region between the __ and __

    • RER cisternae
    •  first transport vesicles
    • biosynthetic 
    • transport vesicles
    • ER and Golgi complex
  22. 1.      this region is called __, and the vesicular-tubular carriers that form these are called __
    a.      once formed, the __move farther away from the ER toward the __
                                                                ii.      movement of __occurs along tracks composed of microtubules
    • ERGIC (ER Gogli intermediate compartment)
    • VTCs
    • VTCs 
    • Golgi complex
    • VTCs

What would you like to do?

Home > Flashcards > Print Preview