Week 9: Cell MotilityW

Which direction do kinesin proteins move?

from minus end to plus end

Which direction do dynein proteins move?

from plus end to minus end

What are the motor proteins for microtubules

dynein and kinesin

When cAMP is increased when melanosomes in cells are aggregated at the minus end in the center, what protein is inactivated? 

dynein 

When cAMP is decreased when melanosomes in cells are dispersed throughout the cell, what protein is inactivated?

kinesin

What is myosin?

actin motor protein

How does the myosin lever reset?

when the ATP is hydrolyzed to ADP in the nucleotide binding site

How is the binding of the myosin to the actin strengthened? 

a phosphate is released

The released phosphate triggers the power stroke that moves the actin filament: True or False

True

How does the myosin detach from the actin?

ADP is released and ATP is added in its place

is the rho GTPase active in the front or back of the cell?

back

is the rac GTPase active in the front or back of the cell?

front

what does myosin assemble into?

bipolar filaments

nonmuscle myosin is active where and how?

tail end of cell

the myosin bipolar filaments help the actin filaments slide past eachother and allow forward movement

what structures are at the leading edge of the cell? 

lamellipodium, filopodium

what organization are lamellipodia?

branched network

nucleated by arp2/3wha

what organization are filopodia

tight parallel bundles (nucleated by formin)