BB 314- Unit 6 Cytoskeleton Quiz

Which of the following statements about the cytoskeleton is true? Choose all that apply.

-Intermediate filaments are so named because their size is 'intermediate', compared to the other two. -The cytoskeleton of a cell can change in response to the environment. -The cytoskeleton controls the location of organelles in eukaryotic cells. -The cytoskeleton is made up of three types of protein filaments. -Actin is the smallest filament.

Kinesin and dynein motor proteins each use the energy of _____ to power their movements along ______.

ATP hydrolysis; microtubules

The black lines in the three images below each represent one of the types of skeletal filament. What are they? The nucleus is shown as a grey circular structure near the center of these animal cells.

Image A- microtubules Image B- Intermediate Filaments Image C- Actin Filaments

Select from the drop-down menu the correct cytoskeletal filament that applies to each of the phrases or statements listed below. Phrases/Statements

Monomer that binds ATP- actin filaments Includes keratin and neurofilaments- intermediate filaments Used in the eukaryotic flagellum- microtubules Their stability involves a GTP cap- microtubules Directly involved in muscle contraction- actin filaments Supports and strengthens the nuclear envelope- intermediate filaments A component of the mitotic spindle- microtubules Important for formation of the contractile ring during cytokinesis- actin filaments

_______ are the motor protein that move directionally along actin filaments.

Myosins

In the polymerization in vitro of actin filaments and microtubules from their subunits, what does the "lag phase" correspond to?

Nucleation

Consider this table. If a cell is treated with the drug Vinblastine, which cellular property/process would NOT be affected?

Reformation of the nuclear envelope

For both actin and microtubule polymerization, nucleotide hydrolysis is important for...

decreasing the binding strength between subunits on filaments

In a centrosome (i.e. an MTOC), which structures serve as nucleation sites for the formation of microtubules?

gamma-tubulin rings