Cytoskeletal Element Quiz Questions

44 Questions | Total Attempts: 99

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Cytoskeletal Element Quiz Questions

This is to prpare for exam 3


Questions and Answers
  • 1. 
    The building blocks of a nucleoside are _____
    • A. 

      A pentose sugar and a phosphate group

    • B. 

      A pentose sugar and a nitrogenous base

    • C. 

      A phosphate group and a nitrogenous base

    • D. 

      A pentose sugar, a phosphate group and a nitrogenous base

    • E. 

      A pentose sugar, a phosphate gruop and an amino acid

  • 2. 
    You incubate liposomes with a series of purified proteins nomrally found in the coats of cell transport vesicles. after adding one of them to the liposome mixture, budding of vesicles fromt he liposomes began. what does this mean?
    • A. 

      Liposomes cause the protein to denature

    • B. 

      The protein is involved in the intiation of vesicle formation

    • C. 

      The protein is involved in liposome denaturation

    • D. 

      The protein triggers protein synthesis

    • E. 

      The protein causes the entry of water into the liposomes

  • 3. 
    How and where is the asymmetry of the phospholipid bilayers initially established?
    • A. 

      It is initially established in the Golgi complex during lipid and protein modification

    • B. 

      It is initially established in the ER during lipid and protein synthesis

    • C. 

      It is initially established in the secretory vesicles during lipid and protein modification

    • D. 

      It is initially established in the in the mitochodnria by random insertion into the membranes.

    • E. 

      All of the above

  • 4. 
    In general, how are proteins targeted to specific destinations?
    • A. 

      Sorting signals is located on the gene

    • B. 

      Sorting signals is located on the proteins

    • C. 

      Receptors in trasport vesicle walls that recognize them

    • D. 

      Sorting signals is located on the cellular compartments

    • E. 

      B and c

  • 5. 
    The __-carbon of the sugar of a nucleotide participates in the formation of the phosphodiester bond?
    • A. 

      1

    • B. 

      2

    • C. 

      3

    • D. 

      5

    • E. 

      C and d

  • 6. 
    Which of the following are pathways of vesicle trafficking through the cytoplasm that have been discovered?
    • A. 

      Biosynthetic pathway

    • B. 

      Secretory pathway

    • C. 

      Endocytic pathway

    • D. 

      Hydrolytic pathway

    • E. 

      A, b and c

  • 7. 
    Which of the models below suggests that the Golgi cisternae are transient structures that form at the cis face of the stack by fusion of membranous carriers from the ER and ERGIC and that each cisterna travels through the Golgi complex from the cis to the trans end of the stack, changing in composition as it progresses?
    • A. 

      The cisternal maturation model

    • B. 

      The cargo carrying model

    • C. 

      The vesicular transport model

    • D. 

      The secretory transport model

    • E. 

      The chemiosmotic model

  • 8. 
    What determines the sequence of sugar addition to glycoprteins traveling through the gogli complex?
    • A. 

      Nothing- the sequence is random.

    • B. 

      The spatial arrangement of specific glycosyltransferases that contact proteins as they pass through the Golgi complex

    • C. 

      The concentration of sugars in the Golgi complex

    • D. 

      The sequence of sugars in the Gogli complex

  • 9. 
    Which molecule below is a GTP-binding protein that is requred for the release of a clatherin-coated vesicle from the membrane on which it was formed?
    • A. 

      AP2

    • B. 

      GGA

    • C. 

      Clathrin

    • D. 

      Dynamin

    • E. 

      Opscrin

  • 10. 
    In a pulse-chase procedure, if the chase is longer, which statement below correctly describes the location of the radioactively labeled proteins in the cell?
    • A. 

      Closer to the synthesis site

    • B. 

      Farther from the nucleus

    • C. 

      Farther from the synthesis site

    • D. 

      Closer to the nucleus

  • 11. 
    Which of the following is (are) made on free ribosomes?
    • A. 

      Proteins that are to remain in the cytosol

    • B. 

      Peripheral proteins of the inner cell membrane surface

    • C. 

      Peripheral proteins of the outer cell membrane surface

    • D. 

      Proteins to be transported to the nuclelus

    • E. 

      A, b and d

  • 12. 
    How are proteins normally resident in the ER retrieved when they escape the ER?
    • A. 

      Proteins that normally reside int he ER lumen have short amino acid sequences at their C-terminus that serve as retrieval sequences.

    • B. 

      Proteins that normally reside int he ER lumen have short amino acid sequences at their N-terminus that serve as retrieval sequences.

    • C. 

      Proteins that normally reside int he ER membrane have short amino acid sequences at their C-terminus that serve as retrieval sequences.

    • D. 

      Proteins that normally reside int he ER membrane have short amino acid sequences at their N-terminus that serve as retrieval sequences.

    • E. 

      A and c

  • 13. 
    To what site does Sar1 bind after it binds to GTP?
    • A. 

      The luminal leaflet of the ER membrane

    • B. 

      The cytosolic leaflet of the Golgi membrane

    • C. 

      The luminal leaflet of the Gogle membrane

    • D. 

      The cytosolic leaflet of the ER membrane

  • 14. 
    Which type of cytoskeletal element is characterized as a hollow, rigid cylindrical tube with walls coposed of tubulin subunits
    • A. 

      Microfilaments

    • B. 

      Microtubules

    • C. 

      Intermediate filaments

    • D. 

      All of the above

  • 15. 
    What endosome serves as a sorting station that directs different types of receptors and ligands along diferent pathways?
    • A. 

      Medial endosomes

    • B. 

      Late endosomes

    • C. 

      Early lysosomes

    • D. 

      Medial lysomes

    • E. 

      Early endosomes

  • 16. 
    The heads of kinesin like proteins have farily closely related amino acid sequences but diverse tail sequences. what ist he explation for this seeming contradiction?
    • A. 

      The similarity of kinesin like protein heads and the variation in their tails are purely random

    • B. 

      The similarity of the heads is explained by their similar roles in interacting with microtubules; the variation in the tails reflects the variation of cargoes to which they bind

    • C. 

      The similarity of the heads is explained by their different roles in interacting with microtubules; the variation in the tails reflects the similar cargoes to which they bind.

    • D. 

      The similarity of the heads is explained by their similar roles in interacting with microtubules; the variation in the tails reflects the similar of cargoes to which they bind

    • E. 

      The similarity of the heads is explained by their different roles in interacting with microtubules; the variation in the tails reflects the variety of cargoes to which they bind.

  • 17. 
    Why is the Er so well-suited and ideally constructed for its role as a port of entry for secretory proteins?
    • A. 

      It has a large surface area allowing the attachment of many ribosoems

    • B. 

      The ER cisternae lumen favors the folding and disassembly of proteins

    • C. 

      The RER segregates secreotry, lysosomal and plant-cell vacuclar proteins from toher newly made proteins, allowing their modication, and sends them to their destination

    • D. 

      A and c

    • E. 

      A, b and c

  • 18. 
    The vesicle is targeted to the appropriate compartment by
    • A. 

      Endocytosis

    • B. 

      Rabs

    • C. 

      GTP binding proteins

    • D. 

      T-snares

  • 19. 
    Avery, MacLead, and McCarty (1944) demonstrated that DNA was the molecule of heredity by treating heat killed Streptaccacus pneumonia A (smooth) strain with DNase, thereby preventing transfer of the transforming substance from the killed S straight to the live R (rough) straight when the two were mixed together and injected into mice. Another way that one could demonstrate transformation in bacteria would be to extract DNA from
    • A. 

      A R straight and mix it with S cells

    • B. 

      A S strain and mix it with R cells

    • C. 

      A S strain and mix it with heat-killed S cells

    • D. 

      None of the above

  • 20. 
    The uptake (both specific and nonspecific) of fluid, dissolved solutes and suspended macromolecules is called ____
    • A. 

      Endocytosis

    • B. 

      Phagoctyosis

    • C. 

      Autophagy

    • D. 

      Exoctyosis

    • E. 

      Pinocytosis

  • 21. 
    A small subfamily of kinesines moves toward the minus end of a microtubules, while the rest move toward the plus end. when the neck and stalk of a minus-directed kinesin is joined to the head of ap lus-directed kinesin, in what direction will the hydrid motor protein travel along a microtubule?
    • A. 

      In a retrograde direction

    • B. 

      Toward the plus-end of the microtubule

    • C. 

      In an anterograde direction

    • D. 

      Towards the fastest growing end of the microtubule

    • E. 

      C and d

  • 22. 
    What recognizes the signal sequence as it exits the ribosomes and of what is it made?
    • A. 

      Signal recognition particle, DNA and protein

    • B. 

      Signal recognition particle, carbohydrate and protein

    • C. 

      SRP and its components, RNA and protein

    • D. 

      Signal recognition protein, carbohydrate and lipid

  • 23. 
    Which of the following are components of Chargaff's rules of bases?
    • A. 

      Amount of G= Amount of C

    • B. 

      Amount of purines= Amount of pyrimidines

    • C. 

      %C+T=%A+G

    • D. 

      Amount of A= Amount of T

    • E. 

      All of the above

  • 24. 
    In addition to microtubule motor proteins ____ are also involved in vesicular transport.
    • A. 

      Actin

    • B. 

      Non-muscle myosins

    • C. 

      Tubulin

    • D. 

      Dynein

    • E. 

      Kinesin-like proteins

  • 25. 
    Most vesicles budding from the Golgi body have a fuzzy, electron-dense coat on their ______ surface. The coat appears to be made of _______.
    • A. 

      Luminal, lipid

    • B. 

      Cytosolic, lipid

    • C. 

      Cytosolic, carbohydrate

    • D. 

      Luminal, protein

    • E. 

      Cytosolic, protein

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