Exam 2 Short answer and multiple choice questions
The outer diameter of a microtubule is ....... nm.
25
The number of amino acids in an actin monomer is: - 375 - 450 - 460-780 - 750
375
The diameter of the actin filament is ...... nm
7
Which of the following statements is NOT true? - Intermediate filaments and actin filaments treadmill. - Intermediate filaments and microtubules have a single monomer. - Intermediate filaments and microtubules have a role at the centrosome. - Two of the above. - All of the above.
All of the Above
The preassembled carbohydrate tree is added on....... Residue.
Asparagine
At steady state equilibrium, microtubules in a test tube have a ....... and .....end.
Assembly, disassembly
What causes a myosin II molecule to be able to form a bipolar fiber? - Myosin I. - Myosin - like chain kinase. - Calcium binding to calmodulin. - Two of the above. - Three of the above
Calcium binding to calmodulin.
he 9+0 configuration refers to......, and is found only in ........cells.
Centrioles, animal
In a living cell, which end of the microtubule is effectively capped?.........
Disassembly end
An organic precipitation works because the solvent _________ disrupts the __________ of the solute.
Ethanol, hydrogen bonding or shell of hydration
True or False: A half patch signal will get a protein half way into the nucleus.
False
True or False: A hemidesmosome connects one cell to another.
False
True or False: Actin filaments will only assemble in parallel bundles.
False
True or False: Constitutive exocytosis routinely requires more signal sequences than regulative exocytosis.
False
True or False: Desmosome junctions are calcium-dependent but cadherin junctions are not.
False
True or False: In neurons, actin filaments are really intermediate filaments
False
True or False: Intermediate filaments assemble and disassemble in a living cell.
False
True or False: Intermediate filaments have no more strength than a microtubule dimer.
False
True or False: Nuclear lamins differs in all the different cell types of an organism:
False
True or False: The carbohydrate tree added to proteins targeted to the primary lysosome is added on an amino acid different from the amino acid where the carbohydrate tree is added to a transmembrane protein.
False
True or False: The dynactin complex acts only on actin filaments.
False
True or False: The inside/outside rule applies only to regulative exocytosis.
False
True or False: The nuclear lamins have no connection with the outside of the nucleus.
False
True or False: The nuclear pore complex provides a site that always lets proteins into the nucleus
False
True or False: Treadmilling of actin filaments only occurs in a test tube.
False
The electron dense cloud surrounding the centrioles in animal cells contains nucleation sites for: MTs made out of alpha and beta subunits MTs made of gamma tubulin does not exist; it is just an artifact of electron microscopy all of the above none of the above
MTs made of gamma tubulin
The molecular weight of intermediate filaments is: - 45 kDa - 42 kDa - 66 kDa - 55 kDa - None of the above
None of the Above
The number 6 carbon of mannose is exposed: - in the nucleus - in the rough endoplasmic reticulum - in the smooth endoplasmic reticulum - in the medial phase of the Golgi - None of the above
None of the above
Gamma-tubulin is present in ......
The centrosome
The intracellular preference for microtubules is .............
The centrosome
When a membrane vesicle leaves the endoplasmic reticulum, ........... assembles into ......... using ......... to produce a vesicle.
Triskelion, clathrin, ATP
During vesicular transport, which of the following are the correct sequences of events as a vesicle leaves the organelle? - Triskelion, clathrin, recycle, Rab, SNARE - Triskelion, clathrin, Rab, SNARE - SNARE, Rab, triskelion, clathrin, recycle - Triskelion, clathrin, recycle - Triskelion, clathrin, SNARE, Rab
Triskelion, clathrin, recycle, Rab, SNARE
Preassembled nucleaton sites in a living cell are equivalent to the intracellular preference for actin filaments
True
True or False: A lipase is a protein.
True
True or False: Actin filaments associate with a nucleotide triphosphate.
True
True or False: At the trans face of the Golgi, triskelion assembles into clathrin to cause removal of the putative primary lysosome.
True
True or False: BiP is a chaperone.
True
True or False: COP I can have a role in the position of protein disulfide isomers.
True
True or False: Desmin is present in muscle cells.
True
True or False: Gap junctions in plant cells cannot close.
True
True or False: Homogenization buffer can be identical to an intracellular buffer.
True
True or False: It is important to be able to repeatedly fractionate the cell.
True
True or False: Microtubules transport new membrane in the form of vesicles to the golgi apparatus from the ER.
True
True or False: One of the reasons that intermediate filaments have strength is the same reason that bipolar fibers of myosin II have strength.
True
True or False: The barrier function of an epithelium extends the role of the plasma membrane over a larger surface area.
True
Actin filaments will - undergo treadmilling in a test tube. - undergo treadmilling in a living cell. - never reach equilibrium. - two of the above.
Two of the above (A and C)
The ability of actin filaments to disassemble into small monomers: - enables the building blocks of actin filaments to move from one side of the cell to the other. - is not relevant to actin filaments. - is relevant to treadmilling. - two of the above. - None of the above
Two of the above (A and C)
The proton pump that lowers the pH below 5.5 or lower i the forming primary lysosome starts working in: - the medial face of the Golgi Apparatus - in the trans face of the Golgi Apparatus - after clathrin has been recycled. - None of the above. - All of the above.
after clathrin has been recycled.
Molecular motors working with microtubules: - are calcium-dependent ATPases - use microtubule singlets and doublets - use microtubule singlets and triplets - two of the above - none of the above
are calcium-dependent ATPases
Tight junctions: - set up a geography of the lipid layer of the cell and only let small molecules but not water pass through. - set up a geography in the proteins of the membrane and let only water but not small molecules pass through. - set up a geography of membrane proteins but adhering junctions stop the water from passing through. - are protected by the strength of adhering junctions. - are made out of only one type of protein
are protected by the strength of adhering junctions.
The binding of the signal recognition particle to the nascent peptide .................... protein synthesis.
arrests
To move cargo from one side of the cell to the other, the sequence would be in the following order: - kinesin, centrosome, plasma membrane - kinesin, centrosome, dynein - plasma membrane, centrosome, kinesin, - kinesin, nucleus, dynein - dynein, centrosome, kinesin
dynein, centrosome, kinesin
Actin filaments: - have a diameter of 7 nm and contain 375 amino acids. - are composed of 2 subunits each of molecular weight of 42 kDa. - have a diameter of 7 nm and contain 450 amino acids. - have no polarity. - have GTP in each of the monomers. - The correct answer is not listed.
have a diameter of 7 nm and contain 375 amino acids.
Hydrolysis of ATP to ADP: - helps identify the assembly vs the disassembly end - is used in dynamic instability - has a role when the actin filament is in chemical equilibrium with - - the actin filament monomers - is important for the nucleation site
helps identify the assembly vs the disassembly end
Treadmilling can occur: - only for the microtubule. - in a test tube for actin filaments and microtubules. - but is overridden by dynamic instability. - only when GTP is hydrolyzed to GDP. - when the alpha and beta subunits bind to GDP.
in a test tube for actin filaments and microtubules.
The monomer of tubulin: - has 3 subunits in it. - is a monomer with a molecular weight of 42 kDa. - is a dimer with a molecular weight of 220 kDa. - is a heterodimer with a total molecular weight of 110 kDa. - None of the above.
is a heterodimer with a total molecular weight of 110 kDa.
Intracellular preference for actin filaments : - is a way to look a the geography of the cell and the role of the nucleus. - is a way to look at the geography of the cell and show where the role of actin filaments is important. - explain how actin gets into the nucleus. - explain how the Golgi Apparatus forms. - two of the above.
is a way to look at the geography of the cell and show where the role of actin filaments is important.
Dynein is a molecular motor that: - moves cargo to the plasma membrane - moves cargo to actin filaments - moves cargo to the centrosome - acts as an actin filament - none of the above
moves cargo to the centrosome
After homogenization the first centrifugation pellets the ________ nucleus or nuclei
nucleus or nuclei
A sucrose gradient is used to purify ________ away from other ________.
plasma membrane, membrane parts or membrane component
The receptor for mannose-6-phosphate caps the proteins destined for the primary lysosome at the: - smooth endoplasmic reticulum - medial face of the Golgi - trans face of the Golgi - two of the above - in the primary lysosome
trans face of the Golgi
The function of the stop- transfer and start-transfer sequences is to make a ..................... protein.
transmembrane
The subunit of clathrin is.......
triskelion
