lecture 6 Flashcards
what are stress fibers?
actin bundles that can contract and produce force
long actin filaments interconnected and have myosin within them
what does myosin do with stress fibers?
myosin helps it with contraction
what do formins do?
polymerize linear actin filaments
what are the two formin domains?
FH1: domain binds profilin-actin (ARMS)
FH2: uneven donut
how many monomers do formins add before detaching?
10000
whats a motor protein, give an example of one?
converts chemical energy into mechanical work
example: myosin (causes force that contracts actin)
what are the subunits of myosin?
actin binding site
-nucleotide binding site (hydrolyzes atp)
-lever arm
what was the glass slide experiment with myosin?
purify actin and myosin from muscle fibers, put myosin motor domain on glass and then add actin filaments on myosin. myosin will crowd surf
different types of myosin?
what does myosin II do
non-muscle myosin II forms bundles that pull actin filaments inward
true or false, different actin networks exist at the front and back of the cell
true
what is the actin network at the front of the cell
leading edge
what is the actin network at the back of the cell
stress fibers
what is the dictyostelium?
an amoeba that aggregates with other amoeba upon starvation
if starved, undergo transition where they all stream towards each other, and form a slug and extend to form fruiting body, which will then detach and blow away in hopes that will find food when they leave
what do the amoebas release which attracts other amoebas?
cyclic AMP
what do rho family GTPases do?
trigger the 3 types of actin network
