Chapters 16 Study Questions
IMPORTANT – All of these questions have multiple answers. You will be given FULL POINTS if you can
use facts described in class and create a logically experiment or suggestion.
A1. Integrins are transmembrane proteins that link the cellular cytoskeleton to the extracellular matrix.
You use RGD peptides to link a magnetic bead to the cell cytoskeleton and use a magnetic field to
twist the beads. You record that the cytoskeleton resists the bead twisting. You want to understand
which components of the cytoskeleton are providing the resistive load. Can you suggest some
experiments to probe this further. (Any one of the answers listed is acceptable for full points.
Other answers along these lines are also acceptable)
State a hypothesis and an experiment to test it.
1) Hypothesis – Intermediate filament cytoskeleton is likely the main resistive element to the twisting
force.
Experiment – Use drugs or genetic approaches to depolymerize actin, microtubule, or
intermediate filament cytoskeleton to test which among these contributes to the response.
2) Hypothesis – Cells response is not linear to the amount of force being applied.
Experiment – Vary the twisting force using the magnetic field strength and see if the angle of twist
varies linearly with the strength of the magnetic field.
3) Hypothesis – Cells can remodel their cytoskeleton, and so if you keep applying force the resistive
load will change with time.
Experiment – You apply a twisting load and release it. Wait 10 min then apply it again and
release it.
