Actin filaments:
a) have a diameter of 7 nm and contain 375 amino acids.
b) are composed of 2 subunits each of molecular weight of 42 kDa.
c) have a diameter of 7 nm and contain 450 amino acids.
d) have no polarity.
e) have GTP in each of the monomers.
f) The correct answer is not listed. ANS f) The correct answer is not listed.
Actin filaments will
a) undergo treadmilling in a test tube.
b) undergo treadmilling in a living cell.
c) never reach equilibrium.
d) two of the above.
e) none of the above. ANS d) two of the above.
The number of amino acids in an actin monomer is:
a) 375
b) 450
c) 460 -780
d) 750
f) none of the above ANS a) 375
Hydrolysis of ATP to ADP:
a) helps identify the assembly vs the disassembly end
b) is used in dynamic instability
c) has a role when the actin filament is in chemical equilibrium with the actin filament monomers
, d) is important for the nucleation site
e) none of the above ANS a) helps identify the assembly vs the disassembly end
Actin filaments associate with a nucleotide triphosphate.
a) True
b) False ANS a) True
Treadmilling of actin filaments only occurs in a test tube.
a) True
b) False ANS b) False
Preassembled nucleation sites in a living cell are equivalent to the intracellular preference for actin
filaments
a) True
b) False ANS a) True
Intracellular preference for actin filaments :
a) is a way to look a the geography of the cell and the role of the nucleus.
b) is a way to look at the geography of the cell and show where the role of actin filaments is
important.
c) explain how actin gets into the nucleus.
d) explain how the Golgi Apparatus forms.
e) two of the above. ANS b) is a way to look at the geography of the cell and show where the role
of actin filaments is important.
The ability of actin filaments to disassemble into small monomers:
a) enables the building blocks of actin filaments to move from one side of the cell to the other.
b) is not relevant to actin filaments.
c) is relevant to treadmilling.
d) two of the above.